🔬 Microbiologic Studies & Biopsies

No acid-fast bacilli seen on any of the submitted smears.

Ordered as the fast first look for mycobacterial infection when a patient has a chronic productive cough, hemoptysis, night sweats, weight loss, an abnormal chest film, or a known tuberculosis exposure. Because it returns in hours rather than weeks, it is also used to judge how infectious a patient is and to follow whether a patient on treatment is clearing organisms.

Mycobacteria have a waxy mycolic acid cell wall that holds onto stain even when the slide is washed with acid-alcohol, which is what makes them acid-fast. The smear is stained and read directly under the microscope, and the report is graded by how many organisms are seen per field. It tells you organisms are present, but not which species and not whether they are alive.

There is essentially no risk to the patient from the stain itself. Sputum induction with hypertonic saline can trigger bronchospasm in a patient with reactive airways. The real hazard belongs to staff and other patients, because the collection generates infectious aerosols.

The smear needs a large number of organisms per milliliter to turn positive, so a negative smear does not rule out tuberculosis. It cannot separate Mycobacterium tuberculosis from nontuberculous mycobacteria, and it cannot tell live organisms from dead ones, so patients on treatment can stay smear positive. Saliva instead of deep sputum, mouthwash or oily lozenges before collection, and antituberculous drugs started before the specimen was taken all lower the yield.

Put the patient in airborne isolation in a negative-pressure room and wear a fit-tested N95 or higher respirator before you go in. Collect the number of specimens your protocol requires, classically three, on separate days and first thing in the morning when secretions have pooled overnight. Have the patient rinse the mouth with plain water only, never antiseptic mouthwash. Increase fluids the evening before to loosen secretions unless contraindicated. Teach the difference between spitting and coughing up sputum from deep in the chest, and collect before anti-TB drugs are started.

Keep the patient in the negative-pressure room, or for an outpatient use a collection booth or an outdoor area away from other people. Sit the patient upright, coach several slow deep breaths and then a hard cough from the diaphragm, and collect into a sterile leakproof container without touching the inside. Stand out of the cough plume and keep your respirator on. Label with the date, exact time and source of the specimen.

Send the specimen to the laboratory promptly and refrigerate it if transport is delayed. Give oral care and let the patient rest. Keep airborne precautions in place until the provider discontinues them; a single negative smear does not lift isolation. Document the amount, color and consistency of the sputum and the patient's tolerance.

A positive smear means acid-fast organisms are present and, in the right clinical setting, that the patient should be treated as infectious right now. Culture is still required to name the species and to guide drug therapy, because nontuberculous mycobacteria look identical on the smear.

Treat a positive AFB smear as proof the patient is infectious today: airborne isolation and N95 respirators stay on until the provider clears them, and precautions start on suspicion rather than waiting for any result.

No growth after the full incubation period, commonly five days.

Ordered whenever bloodstream infection is suspected: sepsis, shaking chills with fever spikes, fever of unknown origin, suspected infective endocarditis, a possible infected central line or prosthetic device, and unexplained hypotension or acute confusion in an older adult. The sensitivity portion tells the team which antibiotic will actually kill the organism so empiric broad-spectrum therapy can be narrowed.

Blood is drawn under strict aseptic technique and injected into paired bottles, one aerobic and one anaerobic, which are incubated and monitored for bacterial or fungal growth. Anything that grows is identified and then exposed to a panel of antibiotics, and the report grades each drug as sensitive, intermediate or resistant.

Physical risk is limited to the venipuncture itself, with hematoma, local pain and rare nerve irritation. The bigger clinical risk is a contaminated culture, which can commit a patient to days of unnecessary antibiotics, a longer stay and a central line they did not need.

Antibiotics given before the draw are the classic cause of a falsely negative culture. Inadequate blood volume in the bottles is the single most common reason a real bacteremia is missed. Poor skin antisepsis or drawing through an existing line grows skin flora such as coagulase-negative staphylococci and diphtheroids and produces false positives. Drawing all bottles from one site removes your ability to tell contamination from true infection.

Collect the cultures before the first dose of antibiotic. Plan for at least two sets, drawn from two separate venipuncture sites, with each set consisting of one aerobic and one anaerobic bottle; a third set is added when endocarditis is suspected. Scrub the skin with chlorhexidine using friction for the full contact time and let it dry completely before you touch the site again, and disinfect the rubber bottle tops with alcohol. Adult volume matters more than anything else you will do here, roughly ten milliliters per bottle. If the order specifies timing with a fever spike or chills, draw then.

Maintain aseptic technique and do not repalpate the prepped site with an ungloved finger. Follow your laboratory protocol for bottle order; with a winged collection set the aerobic bottle is filled first so the air sitting in the tubing does not enter the anaerobic bottle. Fill to the marked line, invert gently, and label each bottle with the exact draw site and time so the microbiologist can interpret a positive.

Send the bottles to the laboratory immediately and do not refrigerate them, because the organisms must stay alive. Give the ordered antibiotic as soon as the specimens are in hand. Continue to monitor for sepsis physiology, including rising heart rate, widening pulse pressure then hypotension, tachypnea, mottling, decreasing urine output and altered mental status, and follow up preliminary Gram stain results, which often return within a day.

Growth confirms bacteremia or fungemia and names the organism. The same organism growing in both sets, from separate sites, is a true bloodstream infection. A single bottle growing skin flora usually reflects contamination, but in a patient with a prosthetic valve, line or joint it may be real and needs provider judgment rather than a nursing assumption.

Draw blood cultures before antibiotics are hung, from two separate sites, with full bottle volume; in a septic patient never let the draw delay the antibiotic past the ordered time window, but never give the drug first if a competent draw can be done immediately.

Red cells uniform in size and shape with central pallor about one-third of the cell diameter, no nucleated red cells, a normal white cell differential with mature segmented neutrophils predominating, adequate and normally sized platelets, no blasts and no organisms.

Ordered to look directly at the cells when an automated count is abnormal or flagged, and to work up anemia, unexplained bruising or bleeding, thrombocytopenia, suspected leukemia or lymphoma, suspected hemolysis, and suspected blood-borne parasites such as malaria or babesiosis. It is also used to confirm and characterize sickle cell disease and to monitor patients on chemotherapy.

A drop of blood is spread in a thin film across a slide, stained, and examined under the microscope. The reader assesses red cell size, shape and color, counts and classifies white cells, estimates platelet number and looks for inclusions, parasites and immature cells that an automated analyzer cannot classify.

None beyond routine venipuncture: brief pain, bruising, hematoma and rare syncope.

Blood left sitting in an anticoagulant tube before the slide is made develops artifacts such as crenated cells and vacuolated neutrophils. A clotted, hemolyzed or underfilled tube is unusable. Recent transfusion masks the patient's own red cell picture. A smear that is too thick, poorly spread or poorly stained cannot be read. For malaria, specimens must be timed to the fever pattern and repeated, because a single negative smear does not exclude it.

Explain that this is a routine blood draw with no fasting and no fluid restriction. Use the tube type the laboratory specifies, usually the lavender-top anticoagulant tube. Note recent transfusions, current chemotherapy and any antibiotics on the requisition. For suspected malaria, coordinate the draw with the fever spike and expect serial specimens.

Perform routine venipuncture, fill the tube to the line, and invert gently rather than shaking, since rough handling ruptures cells. Get the specimen to the laboratory quickly so the slide can be made while the cells are fresh.

Hold pressure, check the site for hematoma, and let the patient resume normal activity. Watch for the preliminary result, because some smear findings need same-day action.

Small pale red cells suggest iron deficiency, while large red cells with hypersegmented neutrophils suggest B12 or folate deficiency. Sickled cells confirm sickling disorders. Fragmented red cells, called schistocytes, point to a microangiopathic process such as DIC, TTP or HUS. Spherocytes suggest hemolysis, target cells suggest thalassemia or liver disease, and Howell-Jolly bodies suggest an absent or nonfunctioning spleen. Blasts indicate acute leukemia. Organisms inside red cells indicate malaria or babesiosis.

Blasts or schistocytes on a smear are not routine laboratory data; report them to the provider the same day, because both represent conditions that deteriorate quickly.

Cellularity appropriate for the patient's age, orderly maturation of all cell lines, blasts under five percent, adequate megakaryocytes, stainable iron present, no fibrosis and no foreign or malignant cells.

Ordered for unexplained cytopenias or pancytopenia, to diagnose and stage leukemia, lymphoma, myeloma and myelodysplastic syndrome, to evaluate aplastic anemia, to assess iron stores when serum studies are ambiguous, to look for metastatic tumor, granulomas or infection in the marrow, and to judge response after chemotherapy or transplant.

The posterior iliac crest is the usual site. A needle is advanced through the cortex, a syringe pulls up liquid marrow for cell morphology, flow cytometry and cytogenetics, and a larger trephine needle removes a solid core of bone and marrow that shows overall cellularity and architecture. Both samples are usually taken at one sitting.

There is no absolute contraindication, because the test is often needed precisely in patients with low counts. Severe inherited bleeding disorders require factor replacement first. Avoid a site that has been irradiated, is infected, or has been previously fractured or grafted. Sternal aspiration is avoided in children and in anyone with osteoporosis or a chest deformity.

Bleeding and hematoma at the site are the main complications and are more likely with thrombocytopenia, anticoagulation or an underlying coagulopathy. Local infection and, rarely, osteomyelitis can occur. Persistent site pain is common for a few days. Sternal aspiration carries a rare but catastrophic risk of penetrating the inner table of the sternum into the mediastinum, heart or great vessels.

A dry tap occurs when the marrow is fibrotic or so packed with cells that nothing can be aspirated, and it does not mean the procedure failed. Dilution with peripheral blood makes the aspirate unrepresentative. A core that is too short or crushed cannot be assessed for cellularity. Recent chemotherapy or growth factor therapy changes the picture. Aspirate that clots before slides are made is useless.

Obtain signed informed consent. Check and document the CBC with platelet count and the PT/INR and aPTT, and report abnormal values before the procedure. Confirm anticoagulants and antiplatelet drugs have been held as ordered. Take baseline vital signs. If moderate sedation is planned, confirm NPO status, IV access and monitoring equipment. Position the patient prone or side-lying with knees drawn toward the chest for a posterior iliac crest approach. Teach honestly that local anesthetic numbs the skin and the periosteum but that the aspiration itself produces a brief, strong pulling or aching sensation that cannot be fully blocked.

Help the patient hold the position and stay still, and maintain the sterile field. Coach slow breathing, warn the patient just before the aspiration pull, and give something to hold or press against. Monitor level of consciousness, respirations, oxygen saturation and vital signs if sedation is used. Slides are usually prepared at the bedside immediately, and the core goes into fixative; label everything with the site.

Apply firm direct pressure for at least five to ten minutes, and considerably longer if the patient is thrombocytopenic or anticoagulated, then apply a pressure dressing. Have the patient lie supine on the biopsy site for about thirty to sixty minutes so body weight tamponades the puncture. Check the site and vital signs every fifteen minutes initially, then taper. Give acetaminophen or the ordered analgesic and avoid aspirin and NSAIDs, which promote bleeding. Keep the dressing clean and dry for twenty-four hours with no tub bath, swimming or hot tub. Teach the patient to report bleeding through the dressing, increasing or spreading pain, fever, redness or drainage.

A hypocellular marrow suggests aplastic anemia or marrow suppression. Twenty percent or more blasts indicates acute leukemia. Sheets of plasma cells suggest multiple myeloma. Absent stainable iron confirms iron deficiency, while excess iron suggests chronic disease or overload. Fibrosis suggests myelofibrosis, and clusters of foreign cells indicate metastatic disease.

Position the patient on the biopsy site and hold pressure long enough; bleeding is the complication you are watching for, and it is most likely in exactly the thrombocytopenic patient who needed the test.

Normal squamous and columnar cervical epithelium with no dysplasia, no koilocytic change and no malignancy.

Ordered to follow up an abnormal Papanicolaou result or a high-risk HPV positive test, to evaluate a visible cervical lesion, and to work up unexplained or postcoital bleeding. The biopsy establishes the grade of dysplasia and, critically, distinguishes precancer from invasive cancer, which completely changes treatment.

A colposcope magnifies the cervix after dilute acetic acid, and sometimes iodine, is applied to make abnormal epithelium stand out. Small punch samples are taken from the most abnormal areas, often with a scraping of the endocervical canal. A loop electrosurgical excision or cold-knife cone removes a wedge containing the transformation zone and is both diagnostic and treating.

Heavy menstrual bleeding obscures the view and the procedure is rescheduled. Acute cervicitis, vaginitis or pelvic inflammatory disease should be treated first. Uncorrected coagulopathy is a contraindication. In pregnancy a directed punch biopsy may still be done when cancer is suspected, but endocervical curettage and conization are generally deferred.

Bleeding is the main risk, and after a loop excision or cone it can be delayed by roughly one to two weeks when the eschar sloughs. Infection, significant cramping and vasovagal syncope also occur. Cone biopsy and repeated excisions can cause cervical stenosis and cervical insufficiency, which raises the risk of preterm birth in later pregnancies.

Recent intercourse, douching, tampons or vaginal medications alter the epithelium. An inadequate colposcopy, meaning the transformation zone cannot be fully seen, limits interpretation. Sampling error is real: the biopsy may miss the worst area of the lesion, so a lower-grade biopsy result never fully rules out a higher-grade lesion seen on cytology.

Obtain signed consent. Schedule about a week after menses ends when the cervix is easiest to visualize. Instruct no douching, tampons, intercourse or vaginal medications for twenty-four to forty-eight hours beforehand. Confirm pregnancy status and ask about anticoagulants and bleeding history. Offer an NSAID thirty to sixty minutes before to blunt cramping if not contraindicated. Have the patient empty her bladder, position her in lithotomy with attention to privacy and dignity, and explain that the acetic acid stings briefly and the punch feels like a sharp pinch followed by a cramp.

Assist with positioning, lighting and draping, and stay at the head of the table for support. Hand off and label each specimen by the site it came from, since location determines management. Watch closely for a vasovagal reaction, which is common with cervical manipulation and shows as pallor, sweating, nausea, yawning, bradycardia and faintness; if it occurs, stop, lay the patient flat and elevate her legs. Monsel solution, silver nitrate or cautery is applied for hemostasis.

Let her rest, then sit up and rise slowly. Teach that cramping for a day and a dark, gritty, coffee-ground discharge from the hemostatic solution for several days are expected. Use pads, not tampons. Nothing in the vagina and no intercourse for the interval the provider specifies, commonly one to three weeks and longer after a cone. Avoid heavy lifting and strenuous activity after excisional procedures. Teach her to call for bleeding heavier than a period, soaking a pad in an hour, passing large clots, foul-smelling discharge, fever, or severe pelvic pain, and remind her that this can begin a week or two later.

Results are reported as cervical intraepithelial neoplasia grade 1, 2 or 3, as carcinoma in situ, or as invasive squamous cell carcinoma or adenocarcinoma. Benign findings include polyps, condyloma and chronic cervicitis. The grade determines whether the patient is observed, treated with excision or referred to oncology.

Teach the bleeding rule before she leaves the building, including that heavy bleeding can start one to two weeks later when the scab separates, and make sure she has the follow-up appointment that actually turns this test into cancer prevention.

Negative, meaning Chlamydia trachomatis nucleic acid is not detected.

Used for routine screening of sexually active women under twenty-five and older women with risk factors, screening in pregnancy, and testing anyone with discharge, dysuria, pelvic or testicular pain, postcoital bleeding, proctitis or conjunctivitis. It is also done when a partner tests positive, in newborns with conjunctivitis or afebrile pneumonia, and as a retest around three months after treatment because reinfection is common.

A nucleic acid amplification test detects chlamydial genetic material, which makes it far more sensitive than older culture methods. Acceptable specimens include a first-catch urine, a clinician- or self-collected vaginal swab, an endocervical or urethral swab, and rectal or pharyngeal swabs when those sites were exposed. It is nearly always run together with gonorrhea from the same specimen.

Physical risk is limited to brief discomfort or spotting from a swab. The meaningful risks are emotional and social: distress, relationship conflict and the requirement for partner notification and public health reporting.

Voiding within an hour of collection washes organisms out of the urethra and is the most common reason a urine specimen fails. Collecting a midstream rather than a first-catch specimen does the same thing. Recent antibiotics, douching, vaginal medications and lubricant on the speculum all reduce yield. Testing only urine or cervix when the exposure was rectal or pharyngeal misses infection at those sites entirely.

Take a private, nonjudgmental sexual history that actually establishes which sites were exposed. For urine, instruct the patient not to void for at least one hour and to collect the first twenty to thirty milliliters, not midstream. For swabs, instruct no douching or vaginal products for twenty-four hours and use no lubricant. Confirm you have the manufacturer's collection kit, because the wrong swab or transport tube invalidates the test.

For an endocervical specimen, wipe away excess mucus first, then insert the swab into the os and rotate for several seconds. For a self-collected vaginal swab, give clear written and verbal instructions and allow privacy. Place the swab in the correct transport medium immediately, break at the score line, cap tightly and label with the site.

Reinforce that both the patient and every recent partner must be treated, that she should abstain from sex for seven days after single-dose therapy or until a multi-day course is finished and partners are treated, and that retesting in about three months is standard. Offer testing for gonorrhea, syphilis and HIV. Explain that chlamydia is a reportable condition and the health department may contact her.

A positive result means active infection. Untreated chlamydia ascends to cause pelvic inflammatory disease, tubal scarring, infertility, ectopic pregnancy and chronic pelvic pain, and in men epididymitis. In pregnancy it can be transmitted to the newborn, causing conjunctivitis in the first weeks and pneumonia at one to three months.

Treating the patient alone does not solve the problem; partners must be treated and sex avoided until treatment is complete, or she will simply be reinfected and accumulate tubal damage.

Negative, meaning viral nucleic acid or antigen is not detected. Antibody testing is negative in a person never infected or vaccinated.

Ordered for symptoms such as fever, cough, shortness of breath, sore throat or loss of taste and smell, after a known exposure, for admission and pre-procedure screening, during outbreak investigation in congregate settings, and to distinguish COVID-19 from influenza and RSV when treatment differs.

Nucleic acid amplification, usually RT-PCR, detects viral RNA from a nasopharyngeal, mid-turbinate, anterior nasal or oropharyngeal swab or from saliva, and it is the most sensitive and the confirmatory method. Antigen tests detect viral protein at the point of care within minutes but are less sensitive, particularly in the absence of symptoms or very early in illness. Antibody testing shows past infection or vaccine response and never diagnoses current infection.

Avoid nasopharyngeal swabbing in a patient with recent nasal or transsphenoidal surgery, a known or suspected CSF leak, significant coagulopathy or active epistaxis, or severe nasal obstruction; use an alternative specimen type instead.

Gagging, sneezing, watering eyes, transient discomfort and minor epistaxis. Mucosal injury is rare. The larger risk is occupational exposure for the person collecting the specimen, since coughing and sneezing during collection generate aerosols.

Testing too soon after exposure, before viral load rises, is the most common cause of a false negative. A shallow swab that never reaches the nasopharynx, insufficient dwell time and rotation, and eating, drinking or using mouthwash before a saliva or oral specimen all reduce yield. Wrong transport medium or improper storage invalidates the result. PCR can remain positive for weeks after the patient is no longer infectious, so a positive test does not by itself mean transmissible disease.

Apply the precautions your facility requires, at minimum a mask, eye protection, gown and gloves, and an N95 with eye protection when collection is likely to generate aerosols. Keep the patient masked until the moment of collection. Verify you have the correct swab and transport tube for the testing platform. Explain that the swab feels strange and makes the eyes water but only lasts a few seconds.

For a nasopharyngeal swab, pass the swab straight back along the floor of the nose parallel to the palate rather than upward, to a depth about equal to the distance from the nostril to the ear, leave it in place several seconds and rotate. For anterior nasal collection, swab both nostrils. Place the swab in the tube, break it at the score line, cap tightly and label immediately.

Offer tissues, perform hand hygiene, and disinfect the surfaces and equipment. Instruct a symptomatic patient to isolate while awaiting results. Explain that a negative rapid antigen test in a symptomatic person often needs to be repeated or confirmed by PCR. Continue to monitor symptomatic patients for hypoxia, and teach that increasing shortness of breath, chest pain, confusion or an oxygen saturation drop requires immediate care.

A positive PCR or antigen result indicates current infection and triggers isolation and treatment decisions. A positive antibody test alone indicates past infection or vaccination. A negative result in a symptomatic, exposed patient may simply mean the test was taken too early or the specimen was poor.

A negative rapid antigen test never overrules a symptomatic exposed patient; keep the precautions in place and confirm with PCR.

Endometrium consistent with the phase of the menstrual cycle, either proliferative or secretory, with no hyperplasia, atypia or malignancy. In a postmenopausal woman, atrophic endometrium is the expected finding.

Ordered for abnormal uterine bleeding, for any postmenopausal bleeding, for a thickened endometrial stripe on ultrasound, for atypical glandular cells on cytology, to evaluate infertility and confirm ovulation, and to monitor women on unopposed estrogen or tamoxifen who are at elevated risk of endometrial cancer.

A thin flexible suction catheter is passed through the cervix into the uterine cavity and moved back and forth while suction draws up a strip of endometrium. The tissue is examined for cycle phase, hyperplasia and cancer. It is usually an office procedure without anesthesia and takes only a few minutes.

Pregnancy is the key contraindication, because the procedure can disrupt an intrauterine pregnancy; a pregnancy test is done first in any woman of childbearing age. Also avoid with acute pelvic inflammatory disease, cervicitis or vaginitis, known cervical cancer, and severe cervical stenosis that cannot be safely dilated. Uncorrected bleeding disorder is a relative contraindication.

Strong menstrual-type cramping during and shortly after the procedure is expected. Real complications include bleeding, endometritis, uterine perforation, and vasovagal reaction with bradycardia and syncope. A frequent practical problem is an insufficient sample requiring repeat sampling, hysteroscopy or dilation and curettage.

For evaluating ovulation and luteal function, timing matters and the specimen is taken late in the luteal phase; for bleeding and cancer evaluation, timing matters far less. A scant sample, an atrophic endometrium that yields almost no tissue, and recent hormonal therapy all limit interpretation. A negative biopsy in a woman with persistent bleeding does not close the case, because a focal lesion such as a polyp can be missed.

Obtain signed consent and confirm a negative pregnancy test. Document the last menstrual period and current hormone use. Offer an NSAID thirty to sixty minutes before to reduce cramping unless contraindicated. Have the patient empty her bladder. Position in lithotomy with attention to modesty. Explain honestly that she will feel several minutes of strong cramping similar to a bad period.

Maintain the sterile field and hand off supplies. A tenaculum placed on the cervix causes a sharp pinch, so warn her before it is applied. Stay at her head, coach slow breathing, and watch continuously for vasovagal signs including pallor, diaphoresis, nausea, bradycardia and lightheadedness; if they appear, stop and lay her flat with legs elevated. Place the tissue in the correct fixative and label it.

Let her lie flat a few minutes and rise slowly, since fainting most often happens on standing. Teach that cramping for a day and spotting or light bleeding for several days are normal, that she should use pads rather than tampons, and that she should avoid intercourse and douching for the period ordered, commonly three to seven days. NSAIDs help the cramping. Tell her to report fever above 100.4 degrees Fahrenheit, foul-smelling discharge, heavy bleeding, or worsening rather than improving abdominal pain, which can signal perforation or infection.

Secretory endometrium confirms ovulation occurred. Hyperplasia without atypia is a risk state managed with progestin; hyperplasia with atypia is a true precancer that often coexists with cancer and usually leads to hysterectomy. Endometrial carcinoma requires oncologic referral. Chronic endometritis and atrophy are benign explanations for bleeding.

Postmenopausal bleeding is endometrial cancer until a biopsy proves otherwise, and no biopsy is done in a woman of childbearing age without first confirming she is not pregnant.

There is no single normal value; the pathologist reports the percentage of tumor cell nuclei that stain and the intensity of staining. Negative is generally reported when under one percent of tumor nuclei stain. Normal breast tissue does express some estrogen receptor.

Performed on every newly diagnosed invasive breast cancer and on ductal carcinoma in situ, and repeated on recurrences and metastases because receptor status can change. It predicts whether the tumor will respond to endocrine therapy such as tamoxifen, aromatase inhibitors or ovarian suppression, and it carries prognostic weight. It is also used on some endometrial and other hormone-sensitive tumors.

Immunohistochemistry applies a labeled antibody to the tissue that binds estrogen receptor protein in the cell nuclei, and the stained nuclei are counted under the microscope. It is performed on the core biopsy or surgical specimen, in parallel with progesterone receptor and HER2 testing, and the three results together define the tumor subtype.

The assay itself carries no risk to the patient. All physical risk belongs to the biopsy or surgery that produced the tissue.

Time between removing the tissue and placing it in fixative, called cold ischemia time, degrades receptor protein and can turn a truly positive tumor negative. Fixation that is too brief or excessively prolonged does the same. Decalcified bone specimens are unreliable. Prior neoadjuvant chemotherapy or endocrine therapy alters expression. Specimens that are mostly necrotic or crushed by cautery cannot be scored.

There is no patient preparation for the assay. The preparation that matters is logistical: know before the procedure which containers and fixatives are required and have them at the bedside or in the room, and never place the specimen in saline or leave it sitting out.

The nursing role is specimen stewardship. Get the tissue into the correct fixative promptly or keep it cold as directed, document the exact time the tissue was removed and the time it entered fixative, and label with the patient identifiers, the site and the laterality.

Support the patient through the wait, which is usually several days to a week, and explain that the result is not about how advanced the cancer is but about which drugs will work against it.

An estrogen receptor positive tumor is generally slower growing, has a more favorable prognosis, and is expected to respond to antiestrogen therapy given over years. An estrogen receptor negative tumor will not respond to endocrine therapy and is treated with chemotherapy and other agents. Negative estrogen receptor with negative progesterone receptor and negative HER2 defines triple-negative disease, which is more aggressive and has fewer targeted options.

The result is only as good as the specimen; document when the tissue came out and when it hit fixative, because delay destroys receptor protein and a falsely negative estrogen receptor can cost a patient years of effective therapy.

Negative: no herpes simplex virus DNA detected, no growth on culture, and negative type-specific IgG for HSV-1 and HSV-2.

Ordered to confirm the cause of oral or genital vesicles and ulcers, to type the virus for counseling and prognosis, to evaluate suspected herpes encephalitis, keratitis, or disseminated infection in an immunocompromised patient, and to evaluate a newborn with vesicles, sepsis-like illness or seizures. Serology is used when lesions have healed or are absent and the question is prior exposure.

PCR of a swab taken from the base of an unroofed vesicle detects viral DNA and is the most sensitive method; the same testing is applied to cerebrospinal fluid, ocular specimens and blood. Viral culture also works but is considerably less sensitive, especially once lesions crust. Type-specific IgG antibody testing tells you whether the person has been exposed to HSV-1 or HSV-2 at some point but cannot tell you whether today's lesion is herpes.

Minimal. Swabbing an open ulcer is painful. The main hazard is contact transmission to the collector, so gloves are mandatory and hand hygiene is essential; a herpetic whitlow on a nurse's finger comes from exactly this.

Sampling a crusted or healing lesion instead of a fresh vesicle is the leading cause of a false negative. Failing to unroof the vesicle and swab the base misses the infected cells. Antivirals started before collection reduce yield. The wrong transport medium, or warm and delayed transport, kills the virus for culture. Serology cannot distinguish a new infection from one acquired years earlier, and IgG takes weeks to appear, so it is useless for diagnosing an acute first episode.

Wear gloves and select the newest, fluid-filled lesion rather than a crusted one. Collect before antiviral therapy is started if that is possible without delaying care. Confirm you have the correct viral collection kit and medium. Warn the patient that the swab will sting.

Unroof the vesicle with a sterile needle or the swab, then rub the base firmly to collect cells, since the virus lives inside the cells and not in the fluid alone. Place the swab in viral transport medium immediately, label with the lesion site, and keep it cool as the laboratory directs. For encephalitis, assist with the lumbar puncture and handling of CSF tubes.

Keep lesions clean and dry. Use contact precautions for extensive, neonatal, disseminated or immunocompromised cases. Teach that the virus sheds even when no lesion is visible, that condoms reduce but do not eliminate transmission, that sexual contact should be avoided during prodrome and outbreak, and that a person with an active lesion must not handle newborns or immunocompromised patients. Address the emotional impact honestly.

A positive PCR or culture confirms active infection, and typing guides counseling since genital HSV-2 recurs more often than genital HSV-1. A positive CSF PCR in a febrile patient with altered mental status or seizures means herpes encephalitis, a neurologic emergency. Positive results in a pregnant woman near term influence the decision for cesarean delivery to protect the newborn.

When herpes encephalitis or neonatal herpes is suspected, intravenous acyclovir is started immediately; you never wait for the PCR to return, because the delay causes permanent neurologic damage or death.

Normal hepatocytes in intact lobules with normal portal tracts, no fibrosis, no significant inflammation or fat, no abnormal iron or copper deposition and no malignant cells.

Ordered for persistently abnormal liver enzymes without an explanation, to stage and grade chronic hepatitis B and C, to distinguish simple steatosis from steatohepatitis in fatty liver disease, to diagnose autoimmune hepatitis, hemochromatosis, Wilson disease and drug-induced injury, to evaluate a liver mass, and to evaluate graft dysfunction or rejection after transplant.

After imaging localizes the liver and marks the site, a needle is passed between the lower right ribs into the liver and a core of tissue is withdrawn, usually with ultrasound guidance. When the patient has significant ascites or a coagulopathy, the transjugular route is used instead, threading a catheter from the neck through the hepatic vein so any bleeding drains back into the vascular system.

Uncorrected coagulopathy or thrombocytopenia must be corrected first. Other contraindications include an uncooperative patient who cannot hold still or hold a breath, massive ascites, a suspected hemangioma or other vascular lesion, a suspected echinococcal cyst, biliary obstruction with a tense biliary tree, and infection in the right chest or subphrenic space such as empyema or cholangitis.

Hemorrhage is the major complication, appearing as intraperitoneal bleeding, subcapsular hematoma or hemobilia, and it may not declare itself for several hours. Bile leak causing bile peritonitis follows puncture of a duct. If the needle crosses the pleura the patient can develop pneumothorax or hemothorax. Other risks include puncture of the gallbladder, kidney or colon, infection, and pain referred to the right shoulder from diaphragmatic irritation.

The needle samples a tiny fraction of the liver, so patchy or focal disease can be missed entirely and a fragmented or short core may be inadequate for staging fibrosis. Sampling variability means two cores from the same liver can be staged differently.

Obtain signed informed consent. Check and document PT/INR, aPTT, platelet count and hemoglobin, and confirm type and crossmatch. Verify anticoagulants, antiplatelet agents and NSAIDs have been held for the ordered interval. Keep the patient NPO for the ordered period, commonly four to eight hours. Take baseline vital signs, establish IV access and have the patient empty the bladder. Most important, teach and practice the breathing instruction: the patient must exhale and hold the breath at the end of expiration while the needle is inserted, which stops the diaphragm and liver from moving.

Position the patient supine or in a left lateral position with the right arm raised above the head to spread the ribs and expose the site. Assist with the sterile prep and local anesthetic. Your key job is to cue the breath hold at the exact moment of needle insertion and confirm the patient is holding it, while keeping the patient still and monitoring vital signs, pain and level of consciousness.

Turn the patient onto the RIGHT side with a pillow or rolled towel pressed against the biopsy site for the first one to two hours, so the weight of the liver against the chest wall tamponades the puncture. Then maintain bed rest for the period ordered, commonly several more hours and in some protocols up to twenty-four hours. Take vital signs every fifteen minutes for the first hour, then taper per protocol. The combination of rising pulse, falling blood pressure and increasing abdominal or right shoulder pain is hemorrhage until proven otherwise and must be reported immediately. Also assess for dyspnea, chest pain and decreased breath sounds on the right, which suggest pneumothorax, and for a rigid, tender abdomen with fever, which suggests bile peritonitis. Follow serial hemoglobin as ordered. Teach no lifting, straining or strenuous activity for about a week, no aspirin or NSAIDs, and review the delayed bleeding signs before discharge.

Results describe the stage of fibrosis and grade of inflammation in chronic hepatitis, the presence of steatosis and steatohepatitis, established cirrhosis, iron or copper overload, granulomas, primary or metastatic malignancy, or transplant rejection.

After a liver biopsy the patient lies on the RIGHT side to tamponade the site, and any rising pulse, falling blood pressure or new right shoulder pain is hemorrhage until proven otherwise; call immediately rather than rechecking in an hour.

Normal alveolar, bronchiolar and interstitial architecture with no malignant cells, no granulomas, no fibrosis and no organisms.

Ordered to characterize a lung mass, nodule or persistent infiltrate, to diagnose lung cancer and obtain enough tissue for molecular and biomarker testing that determines targeted therapy, and to diagnose interstitial lung disease, sarcoidosis, vasculitis and infections such as tuberculosis, fungal disease and Pneumocystis when sputum and washings have not answered the question.

Tissue is obtained transbronchially through a flexible bronchoscope, percutaneously with a needle through the chest wall under CT guidance, or surgically by video-assisted thoracoscopy or open thoracotomy when a larger, architecturally intact sample is needed. The approach is chosen by where the lesion sits and how much tissue the diagnosis requires.

Uncorrected bleeding disorder or ongoing anticoagulation, severe pulmonary hypertension, bullous emphysema or cysts at the intended site, a suspected vascular lesion, severe hypoxemia, an uncooperative patient, and a patient with only one functioning lung, in whom a pneumothorax could be fatal.

Pneumothorax is the classic complication of percutaneous and transbronchial approaches and may require a chest tube. Hemoptysis and pulmonary hemorrhage can be significant. Other risks are air embolism, infection or empyema, subcutaneous emphysema, and pain. Both bleeding and pneumothorax can be delayed by hours, which is why post-procedure surveillance matters as much as the procedure.

Sampling error is the main limitation; a small, necrotic or peripheral lesion may be missed. Transbronchial forceps produce crush artifact and samples too small to diagnose diffuse interstitial disease, which often requires surgical biopsy. Antibiotics started before a sample intended for culture lower the yield.

Obtain signed informed consent. Verify CBC, platelet count, PT/INR and type and screen, and that anticoagulants have been held as ordered. Confirm recent chest imaging is available. Keep the patient NPO for six to eight hours, longer for general anesthesia. Document baseline vital signs, oxygen saturation and a careful bilateral breath sound assessment; this baseline is what you will compare against afterward. Establish IV access. Teach the required breath hold and the instruction not to talk or cough while the needle is in place.

Position as directed for the chosen approach and help the patient stay completely still. Monitor oxygen saturation, respiratory rate and effort, heart rhythm and level of consciousness continuously. Coach the breath hold. Report immediately any sudden dyspnea, sharp chest pain, coughing of blood, agitation or desaturation.

A chest x-ray is obtained after the procedure to look for pneumothorax and is often repeated a few hours later, because a pneumothorax can develop late. Take vital signs and oxygen saturation frequently and auscultate both lungs, comparing directly with your pre-procedure baseline. Sudden sharp chest pain, dyspnea, absent or diminished breath sounds on the biopsy side, tracheal deviation, hypotension and tachycardia indicate a tension pneumothorax and are an emergency requiring immediate notification and preparation for chest tube insertion. Expect a small amount of blood-streaked sputum; frank hemoptysis is not expected and must be reported. After bronchoscopy keep the patient NPO until the gag reflex returns. Teach a patient going home to return immediately for sudden breathlessness or chest pain.

Results identify primary or metastatic carcinoma along with the cell type and molecular markers that drive treatment, granulomatous disease such as tuberculosis or sarcoidosis, fungal or Pneumocystis organisms, fibrotic interstitial patterns, or vasculitis.

Pneumothorax is what you are watching for; compare breath sounds against the pre-procedure baseline, and treat sudden dyspnea with chest pain and absent breath sounds on the biopsy side as an emergency rather than something to recheck later.

No chromosomal abnormality detected; cells show the normal two copies of each tested chromosomal region and there is no polysomy.

Added to routine brush cytology when a bile duct or pancreatic duct stricture cannot be classified as benign or malignant. Ordinary brush cytology is highly specific but misses a large share of cancers, so FISH is used to improve detection of cholangiocarcinoma and pancreatic adenocarcinoma, especially in patients with primary sclerosing cholangitis, where chronic inflammation makes cytology very difficult to interpret.

During ERCP a brush is passed across the stricture to collect cells. Fluorescently labeled DNA probes are then hybridized to specific chromosomal regions and the cells are examined for extra copies. Gains of several chromosomes within the same cell, called polysomy, indicate malignancy, while a gain of a single region is far less specific.

The assay itself has no contraindications; the contraindications belong to the ERCP that obtains the specimen, including an uncooperative patient, unstable cardiopulmonary status, recent myocardial infarction, uncorrected coagulopathy and known perforated viscus.

No additional risk comes from the FISH test. The risks are those of ERCP: post-ERCP pancreatitis, which is the most common and most serious, plus bleeding, duodenal or duct perforation, cholangitis, contrast reaction, and respiratory depression or aspiration from sedation.

Too few cells on the brush is the common failure. Reactive atypia from a previously placed stent, from stone disease, or from the inflammation of primary sclerosing cholangitis can mimic or obscure malignant change. Delayed or improper fixation of the brushing degrades the nuclei so probes cannot be scored.

Prepare the patient for ERCP: signed consent, NPO after midnight or for the ordered interval, IV access, coagulation studies and platelet count, allergy history including contrast and shellfish, anticoagulants held as ordered, and baseline vital signs including oxygen saturation.

Assist with sedation, positioning and continuous monitoring of airway, oxygen saturation, rhythm and blood pressure during the ERCP. When the brushing is obtained, make sure it is placed in the fixative the cytology laboratory specifies without delay and labeled with the exact location of the stricture.

Provide standard post-ERCP care. Keep the patient NPO until the gag reflex returns, then advance as ordered. Monitor for post-ERCP pancreatitis, which presents as severe persistent epigastric pain radiating to the back with nausea, vomiting, abdominal distention, fever and rising amylase and lipase. Also watch for signs of cholangitis such as fever, chills and jaundice, for bleeding, and for the abdominal rigidity of perforation. Support the patient through a stressful wait for results.

Polysomy strongly supports malignancy in the stricture and, with consistent imaging and clinical findings, is treated as evidence of cancer. A single-locus gain or trisomy is equivocal and usually leads to repeat sampling and close surveillance. A negative FISH result does not exclude cancer, so a suspicious stricture continues to be followed.

The immediate nursing concern is not the FISH result but the ERCP that produced it: severe, persistent epigastric pain radiating to the back afterward is post-ERCP pancreatitis and must be reported at once.

Negative for intraepithelial lesion or malignancy, with an adequate specimen that includes cells from the transformation zone.

The screening test for cervical cancer and its precursors, performed at the intervals recommended for the patient's age and history, usually in combination with or replaced by high-risk HPV testing. It also incidentally shows infection, inflammation, atrophic change and occasionally endometrial cells that warrant further evaluation.

Cells are scraped from the outer cervix with a spatula and from the endocervical canal with a brush, or from both areas with a single broom device. They are either smeared on a slide and fixed immediately or rinsed into a liquid preservative vial. The laboratory screens the cells for abnormal nuclei, and the same liquid vial can also be used for HPV and sexually transmitted infection testing.

Not performed during heavy menstrual bleeding, which obscures the cells. Remember that the Pap is a screening test, not a diagnostic one: a visible cervical lesion requires biopsy no matter what the cytology says.

Minimal, limited to brief cramping, light spotting and speculum discomfort.

Menstrual blood, douching, intercourse, tampons, vaginal creams, spermicides or lubricant within twenty-four to forty-eight hours before collection all interfere. A recent prior Pap can leave too few cells for the next one. Active infection or heavy inflammation obscures the cells. On a conventional smear, air-drying before fixation destroys the specimen. Failing to sample the transformation zone, where nearly all cervical cancers begin, is the most consequential technical error, and atrophy in postmenopausal women reduces the yield.

Schedule about two weeks after the first day of the last menstrual period and never during menses. Instruct no intercourse, douching, tampons or vaginal medications for twenty-four to forty-eight hours beforehand. Record the last menstrual period, hormone use, prior abnormal results and pregnancy status on the requisition, because the interpretation depends on them. Have the patient empty her bladder. Warm the speculum with water only, since lubricant contaminates the specimen. Position in lithotomy and drape for privacy and dignity.

Assist with lighting, positioning and specimen containers. Encourage relaxed breathing and relaxed thighs, which makes speculum insertion far more comfortable. Fix a conventional slide immediately or rinse the collection device in the liquid vial as directed, then label at the bedside. Document which sites were sampled.

Offer a pad for spotting. Tell the patient exactly when and how she will receive results and who to call if she does not hear. Explain that abnormal results are common and usually reflect changes that are treatable long before they become cancer, and that follow-up is what actually prevents cervical cancer.

Findings include atypical squamous cells of undetermined significance, low-grade and high-grade squamous intraepithelial lesions, atypical glandular cells and carcinoma. Results are interpreted alongside HPV status and lead to repeat testing, colposcopy or biopsy. An unsatisfactory specimen, or one without transformation zone cells, may require a repeat.

A Pap only prevents cancer when the abnormal result is followed up; before the patient leaves, be certain she knows how she will get her result and what the next step will be.

No misfolded alpha-synuclein detected in cerebrospinal fluid or skin; symmetric, normal dopamine transporter uptake in the striatum on imaging; no pathogenic variant on genetic testing; and a neurologic examination without the cardinal motor findings of resting tremor, rigidity, bradykinesia and postural instability.

Parkinson disease is diagnosed clinically, so testing is used to support the diagnosis when the presentation is atypical, to separate Parkinson disease from essential tremor, drug-induced parkinsonism and vascular parkinsonism, to identify people in a prodromal stage, and to identify genetic forms such as LRRK2, GBA1, PRKN and SNCA that matter for family counseling and for eligibility in clinical trials.

An alpha-synuclein seed amplification assay on cerebrospinal fluid, or on a skin punch biopsy, detects misfolded alpha-synuclein protein, the pathologic hallmark of these diseases. Dopamine transporter SPECT imaging uses a radiotracer to show loss of presynaptic dopamine nerve terminals in the striatum. Genetic testing looks for known pathogenic variants. Clear, sustained improvement on levodopa is itself supporting evidence for the diagnosis.

Dopamine transporter imaging is avoided in pregnancy and used cautiously during breastfeeding because of the radiotracer. Lumbar puncture is contraindicated with raised intracranial pressure, infection at the puncture site, or uncorrected coagulopathy.

Lumbar puncture can cause post-dural puncture headache, back pain, transient radicular pain, bleeding and, rarely, infection. Skin punch biopsy risks are small: bleeding, local infection and a small scar. Dopamine transporter imaging involves a small radiation dose and requires a thyroid-blocking agent before the tracer. Genetic testing carries psychological, family and insurance implications rather than physical risk.

Medications that act on dopamine transporters or receptors, including certain antidepressants, stimulants, cocaine and some antipsychotics, can distort dopamine transporter imaging, so a full medication review is mandatory beforehand. A bloody cerebrospinal fluid specimen, the wrong tube type, or improper storage degrades the synuclein assay. No single result overrides a clinical picture that does not fit, and abnormal imaging shows dopaminergic degeneration without naming which degenerative disease is causing it.

For lumbar puncture, obtain consent, verify coagulation studies and platelet count, have the patient empty the bladder, and teach the flexed position. For dopamine transporter imaging, review and hold interfering medications exactly as directed, give the ordered thyroid-blocking agent before the tracer, and screen for pregnancy. For genetic testing, arrange pretest genetic counseling and informed consent that specifically addresses genetic results before any sample is drawn.

For lumbar puncture, help the patient hold the flexed lateral or seated position, maintain sterility, note the opening pressure and the appearance of the fluid, and collect into the specified tubes in order. For imaging, keep the patient still, explain the length of the scan, and reassure a patient whose tremor makes lying still difficult.

After lumbar puncture, keep the patient flat for the ordered period, encourage fluids, and monitor for a headache that worsens when upright, for site leakage or hematoma, and for new neurologic deficits. After skin biopsy, keep the site clean and dry and watch for infection. Regardless of the test, assess safety at home now: falls, freezing of gait, swallowing difficulty and orthostatic hypotension are the issues that actually harm these patients. Provide emotional support, since this is a diagnosis with a long trajectory.

Detection of misfolded alpha-synuclein supports a synucleinopathy, which includes Parkinson disease, dementia with Lewy bodies and multiple system atrophy, but does not distinguish among them. Reduced and asymmetric striatal uptake supports a degenerative parkinsonism and argues strongly against essential tremor or drug-induced parkinsonism. A pathogenic gene variant identifies a hereditary form with implications for relatives.

No laboratory or imaging result diagnoses Parkinson disease by itself; document the motor examination, the medication list and the functional decline carefully, because that clinical evidence is what the diagnosis actually rests on.

A thin, flat layer of mesothelial cells lining the pleura with no inflammation, granulomas, fibrosis or tumor.

Ordered to determine the cause of a pleural effusion or pleural thickening when analysis of the fluid alone did not give an answer, particularly when tuberculous pleuritis, mesothelioma or metastatic pleural disease is suspected.

A cutting needle is passed through an intercostal space to hook and remove a piece of parietal pleura, often at the same sitting as a thoracentesis, and image guidance improves accuracy. When closed biopsy is nondiagnostic, thoracoscopic biopsy under direct vision is used because it samples the abnormal areas the operator can actually see and has a much higher yield.

Uncorrected coagulopathy, thrombocytopenia or ongoing anticoagulation. Also avoid with infection or cellulitis at the entry site, an uncooperative patient who cannot hold still, severe respiratory compromise that would not tolerate a pneumothorax, and an obliterated pleural space.

Pneumothorax is the most common complication and may require a chest tube. Hemothorax from laceration of an intercostal vessel, laceration of lung, liver or spleen, infection, seeding of tumor along the needle tract, vasovagal reaction and significant pain also occur.

Both tuberculous pleuritis and mesothelioma involve the pleura patchily, so a blind closed biopsy can easily sample normal tissue and return a false negative. Too few specimens lowers the yield further. Sending all specimens for histology and none for mycobacterial culture wastes a major part of the diagnostic value, since culture of pleural tissue often finds tuberculosis that histology alone would miss.

Obtain signed informed consent. Verify and document CBC, platelet count and coagulation studies, and that anticoagulants were held as ordered. Have recent chest imaging available. Record baseline vital signs, oxygen saturation and bilateral breath sounds for later comparison. Teach the patient that she must remain absolutely still and must not cough or take a deep breath while the needle is in, and agree on a signal for discomfort.

Position the patient sitting upright leaning forward over a bedside table with the arms supported, or side-lying with the affected side up. Support that position physically and prevent movement. Coach quiet, steady breathing. Monitor pulse, respirations, oxygen saturation and color, and watch for vasovagal signs such as pallor, sweating and lightheadedness. Label specimens and confirm that tissue is sent for mycobacterial and other cultures as well as histology when infection is a consideration.

Apply a pressure dressing and position the patient on the unaffected side to help seal the puncture. Obtain the ordered post-procedure chest x-ray to rule out pneumothorax. Take vital signs and oxygen saturation frequently and auscultate both lungs, comparing with the baseline. Report immediately sudden dyspnea, sharp chest pain, absent or decreased breath sounds on the biopsy side, tachycardia, hypotension, tracheal deviation, or subcutaneous crepitus around the site, since these indicate pneumothorax and possibly tension pneumothorax. Also monitor for hemoptysis, increasing pain, fever and bleeding at the site.

Caseating granulomas point to tuberculous pleuritis. Malignant cells identify metastatic disease or mesothelioma. Nonspecific inflammation or fibrosis is not a diagnosis and usually leads to repeat or thoracoscopic sampling.

Assume pneumothorax until the post-procedure chest film and your own breath sound assessment say otherwise, and treat sudden dyspnea with absent breath sounds on the biopsy side as an emergency.

No pathogenic or likely pathogenic variant identified in the genes tested.

Ordered when the pattern of illness suggests an inborn error of immunity: recurrent, severe, unusual or persistent infections, infections with organisms that do not normally cause disease, deep abscesses, chronic diarrhea and failure to thrive, poor wound healing, autoimmunity combined with infection, a family history of early infant deaths, or an abnormal newborn screen for severe combined immunodeficiency. Naming the specific defect determines whether the treatment is immunoglobulin replacement, prophylactic antimicrobials, hematopoietic stem cell transplant or gene therapy.

DNA extracted from blood or a buccal sample is sequenced across a panel of immune-related genes, or by exome or genome sequencing, and each variant found is classified as pathogenic, likely pathogenic, of uncertain significance, likely benign or benign. Genetic testing complements rather than replaces the functional workup of immunoglobulin levels, specific antibody responses to vaccines, lymphocyte subsets by flow cytometry, neutrophil function studies and complement testing.

There is no physical risk beyond the blood draw. The meaningful risks are informational: variants of uncertain significance that give no answer but create anxiety, incidental findings unrelated to immunity, discovery of nonpaternity or consanguinity, and psychological, reproductive and insurance implications for the patient and relatives.

A recent blood transfusion or a hematopoietic stem cell transplant introduces donor DNA and can make the result uninterpretable, so the transfusion and transplant history must be reported. A panel that does not include the causative gene returns a false reassurance. Mosaicism, deep intronic variants and large structural rearrangements can be missed by standard sequencing. A normal genetic result does not exclude an immune defect when the functional testing is abnormal.

Obtain informed consent that specifically addresses genetic testing and arrange pretest genetic counseling. Take a three-generation family history including infant deaths, consanguinity and recurrent infections. Confirm the correct tube type and whether parental samples are needed for interpretation. Document any recent transfusion or transplant. Tell the family that results usually take weeks, not days.

Perform the venipuncture or buccal collection with the specified tube and technique. Verify patient identity with extreme care and label at the bedside; a mislabeled genetic specimen has consequences that reach across an entire family.

Arrange post-test counseling regardless of the result. In the meantime treat the patient as immunocompromised: reinforce hand hygiene, avoidance of sick contacts and crowds, prompt reporting of fever, and the rule that live vaccines are withheld until immune status is established. Teach the family that fever in a child with suspected severe immunodeficiency is an emergency requiring immediate evaluation, not a wait-and-see at home. Discuss irradiated, CMV-safe blood products if transfusion becomes necessary.

A pathogenic variant confirms a specific inborn error of immunity, directs definitive treatment and identifies at-risk relatives and carriers. A variant of uncertain significance is not a diagnosis and must be correlated with functional immune testing. A negative panel in a patient with abnormal immune function means the evaluation continues rather than ends.

Until immunodeficiency is ruled out, manage the patient as immunocompromised: no live vaccines, and any fever is evaluated urgently rather than observed.

Reported as the percentage of tumor cell nuclei that stain and the staining intensity rather than as a single number; negative is generally reported when under one percent of tumor nuclei stain.

Performed alongside estrogen receptor testing on every invasive breast cancer and on ductal carcinoma in situ, and repeated on recurrences and metastases. It refines the prediction of benefit from endocrine therapy and sharpens the prognosis. Because progesterone receptor expression depends on a functioning estrogen pathway, a positive progesterone receptor also serves as internal evidence that the estrogen receptor result is genuine.

Immunohistochemistry applies a labeled antibody that binds progesterone receptor protein in tumor cell nuclei, and the pathologist reports the proportion of stained tumor cells and the intensity. It is run in parallel with estrogen receptor and HER2 on the same specimen, and the three together define the tumor subtype and the treatment plan.

None directly from the assay; the physical risks belong to the biopsy or surgery that supplied the tissue.

Prolonged cold ischemia time before the tissue reaches fixative, and fixation that is too short or excessively long, degrade the receptor protein and can produce a false negative. Decalcified bone specimens are unreliable. Prior neoadjuvant chemotherapy or endocrine therapy alters expression. Necrotic or cautery-crushed tissue cannot be scored.

No specific patient preparation for the assay. Prepare the patient for the biopsy or operation, and have the correct containers and fixative ready before the specimen exists.

The nursing role is specimen handling: correct fixative, adequate volume of fixative, prompt placement, and documentation of the time of removal and the time of fixation along with patient identifiers, site and laterality.

Support the patient during the wait and explain that estrogen receptor, progesterone receptor and HER2 together determine whether she receives endocrine therapy, chemotherapy, targeted therapy or a combination.

Tumors positive for both estrogen and progesterone receptors respond best to endocrine therapy and carry the most favorable prognosis among receptor groups. Estrogen receptor positive but progesterone receptor negative tumors respond less reliably. Negative for both receptors and negative for HER2 defines triple-negative disease, which will not respond to endocrine therapy.

Progesterone receptor is interpreted together with estrogen receptor, never alone, and like estrogen receptor its accuracy depends entirely on the tissue reaching fixative promptly, so document those times.

Normal glomeruli, tubules, interstitium and vessels on light microscopy, no immune complex deposits on immunofluorescence, and normal ultrastructure including intact podocyte foot processes on electron microscopy.

Ordered for unexplained proteinuria or nephrotic syndrome, glomerular hematuria, acute kidney injury of unclear cause, rapidly progressive renal failure, suspected glomerulonephritis, lupus nephritis or vasculitis, systemic disease with renal involvement, and to evaluate dysfunction or suspected rejection in a transplanted kidney.

With ultrasound or CT guidance, the patient lies prone and a core needle is advanced into the lower pole of the kidney, which is the safest target because it contains fewer large vessels. Usually two cores are obtained and divided so that tissue goes for light microscopy, immunofluorescence and electron microscopy, since many renal diagnoses require all three. A transplanted kidney lies in the iliac fossa and is biopsied with the patient supine.

Uncontrolled hypertension must be treated before the biopsy. Other contraindications include bleeding disorder or ongoing anticoagulation, small shrunken end-stage kidneys, hydronephrosis, active pyelonephritis or perinephric abscess, renal tumor or large cysts at the site, an uncooperative patient who cannot hold still or hold a breath, and, relatively, a solitary functioning kidney.

Bleeding dominates. It ranges from expected microscopic hematuria to gross hematuria, perirenal hematoma, arteriovenous fistula, and occasionally hemorrhage severe enough to require transfusion, angiographic embolization or nephrectomy. Clot in the ureter causes colicky flank pain and can obstruct urine flow. Other risks include infection, arterial puncture, and injury to bowel, liver or spleen. Bleeding may not appear for many hours, which is why the monitoring period is long.

A core containing too few glomeruli is nondiagnostic, and a core containing only medulla misses glomerular disease entirely. Focal diseases can be missed by sampling. The specimen must be divided correctly at the bedside, and tissue destined for immunofluorescence must not be placed in formalin, which destroys the study.

Obtain signed informed consent. Verify and document CBC, platelet count, PT/INR, BUN and creatinine, and type and crossmatch. Confirm anticoagulants, antiplatelet agents and NSAIDs have been held for the ordered interval. Control and document the blood pressure, since hypertension drives post-biopsy bleeding. Keep NPO for the ordered period, establish IV access, and have the patient empty the bladder. Obtain a pre-procedure urine specimen so you have something to compare the post-procedure urine against. Teach and practice the breath hold: the patient takes a breath in and holds it while the needle is inserted so the kidney stops moving with the diaphragm.

Position the patient prone with a pillow, sandbag or rolled towel under the abdomen to push the kidney posteriorly and stabilize it. Maintain that position, cue the breath hold at the exact moment of needle insertion, keep the patient still, and monitor vital signs, pain and level of consciousness. Ensure the cores are divided into the correct media immediately.

Apply firm pressure, then keep the patient on strict bed rest, supine and flat for the ordered period, commonly four to twenty-four hours depending on protocol, with no sitting up, lifting or straining. Take vital signs every five to fifteen minutes at first and then taper; a rising pulse with a falling blood pressure is your earliest sign of bleeding. Inspect the site and flank for swelling, bruising or an enlarging mass. Look at every voided specimen: the first urine is often blood tinged and should progressively clear, so urine that becomes bloodier rather than clearer, or that contains clots, is abnormal. Follow serial hemoglobin and hematocrit as ordered. Encourage fluid intake to flush clots unless the patient is on a fluid restriction. Report flank, shoulder or colicky pain, inability to void, dizziness, hypotension, tachycardia or a falling hematocrit. Before discharge, teach no heavy lifting or strenuous activity for roughly two weeks and to return immediately for gross hematuria, severe flank pain or fainting.

Results identify specific renal diseases such as IgA nephropathy, membranous nephropathy, minimal change disease, focal segmental glomerulosclerosis, lupus nephritis with its class, ANCA-associated vasculitis, diabetic nephropathy, acute tubular necrosis, acute interstitial nephritis or amyloidosis, and in transplants they distinguish rejection from drug toxicity and recurrent disease.

The post-biopsy job is bleeding surveillance: flat bed rest, serial vital signs, and look at every urine specimen; urine that grows bloodier instead of clearer, or a rising pulse with a falling blood pressure, is hemorrhage and is reported immediately.

Normal upper respiratory flora only, with no pathogenic organism isolated.

Ordered to identify the organism causing pneumonia, an infective exacerbation of COPD or bronchiectasis, lung abscess or a cystic fibrosis exacerbation, and to determine which antibiotics will kill it so empiric broad-spectrum therapy can be narrowed to a targeted drug.

Sputum from the lower airway is plated onto culture media, and organisms that grow are identified and tested against a panel of antibiotics, reported as sensitive, intermediate or resistant. A Gram stain is done first and serves two purposes: it gives an immediate clue to the organism, and by counting squamous epithelial cells and white cells it tells the laboratory whether this is genuine lower-airway sputum or mostly saliva.

Minimal for the patient. Sputum induction with hypertonic saline can trigger bronchospasm in a patient with reactive airway disease. Nasotracheal suctioning can cause hypoxia, gagging, vomiting, mucosal trauma and vagally mediated bradycardia.

Antibiotics started before collection are the biggest problem, so collect first. Saliva submitted instead of sputum is the most common reason a specimen is rejected. Oral flora contamination, food particles, and antiseptic mouthwash used before collection all invalidate the result. Delay at room temperature lets contaminants overgrow the true pathogen. Using the wrong container or a nonsterile one ruins the specimen.

Collect the specimen before the first dose of antibiotic. Collect early in the morning on rising, when secretions have pooled in the airways overnight and the yield is highest. Have the patient rinse the mouth with plain water only; antiseptic mouthwash kills the organisms you are trying to grow. Increase fluid intake the evening before to thin secretions unless contraindicated. Give ordered bronchodilators or chest physiotherapy first. Explain clearly the difference between spitting saliva and coughing up material from deep in the chest, because this single teaching point determines whether the specimen is usable.

Sit the patient upright. Coach several slow deep breaths, then a hard cough from the diaphragm, and collect roughly five to ten milliliters directly into the sterile container without touching the inside of the container or lid. If the patient cannot produce sputum, use hypertonic saline induction, nasotracheal suctioning with a sputum trap, or arrange bronchoscopic sampling. Wear appropriate personal protective equipment and stand out of the cough path. Support a fresh surgical incision with a pillow during coughing.

Cap and label the container with the collection time and method, and transport promptly, ideally within an hour, refrigerating only if transport is delayed. Provide oral care. Document the amount, color, consistency and odor of the sputum and the patient's tolerance. Start the ordered antibiotic as soon as the specimen has been obtained, and follow up the Gram stain and preliminary results so therapy can be adjusted.

Growth of a pathogen such as Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus including MRSA, Klebsiella pneumoniae or Pseudomonas aeruginosa identifies the cause of the infection, and the sensitivity panel directs the switch from empiric to targeted therapy. Resistant organisms may also trigger contact precautions.

Get the specimen before the first antibiotic dose and make certain it is sputum and not saliva; a specimen collected after antibiotics or full of spit answers nothing and leaves the patient on broad-spectrum drugs longer than necessary.

Normal bronchial epithelial cells, macrophages and inflammatory cells with no malignant or atypical cells.

Ordered to look for cancer cells in a patient with hemoptysis, a suspicious mass or infiltrate on chest imaging, or a chronic cough in a heavy smoker. Because it is completely noninvasive it is sometimes attempted before bronchoscopy or biopsy. It is also used to look for certain infections and, in occupational evaluation, for asbestos bodies.

Sputum coughed up from the lower airway is examined microscopically for abnormal cells rather than cultured for organisms. The specimen is usually placed directly into a fixative, which is the opposite of what a culture specimen requires, so the container matters.

Minimal. Induction can provoke bronchospasm, and forceful coughing is painful after thoracic or abdominal surgery, so the incision should be splinted.

Saliva instead of deep sputum is the main reason for a nondiagnostic specimen. Yield is much better for central tumors than peripheral ones, because central tumors shed cells into the airway. A single specimen is often not enough, so serial early-morning specimens on consecutive days are usually collected. Delay without proper fixation degrades the cells. Most importantly, a negative result never rules out lung cancer.

Collect first thing in the morning before eating or drinking. Have the patient rinse the mouth with plain water. Confirm you have the correct container, since cytology specimens usually require immediate fixative while culture specimens must remain sterile and unfixed; sending the specimen in the wrong container wastes the collection. Explain that several specimens on consecutive days are often needed.

Position the patient upright, coach several deep breaths and then a deep productive cough from the chest into the container. Splint any surgical incision. If the patient cannot produce a specimen, use nebulized hypertonic saline induction or arrange bronchoscopic washings and brushings.

Label and transport promptly or fix as the laboratory directs. Provide oral care and rest. Document the appearance of the specimen. Prepare the patient for the likelihood that a negative result will still be followed by bronchoscopy or tissue biopsy if imaging is suspicious, so the negative does not create false reassurance.

Malignant cells identify carcinoma and often the cell type; squamous cell carcinoma and small cell carcinoma are detected most readily because they arise centrally. Atypical cells may reflect inflammation, infection, prior radiation or chemotherapy and generally require further evaluation rather than immediate alarm.

A negative sputum cytology does not clear the patient; if the imaging or the clinical picture is suspicious, the workup continues to bronchoscopy or biopsy.

Normal upper respiratory and skin flora; no group A beta-hemolytic streptococcus on a throat culture and no Staphylococcus aureus or MRSA on a nasal screen.

Throat cultures confirm or exclude group A streptococcal pharyngitis, especially as backup after a negative rapid antigen test in a child or adolescent, and with the right media they detect Neisseria gonorrhoeae, Corynebacterium diphtheriae and Bordetella pertussis. Nasal and nasopharyngeal cultures identify MRSA colonization before surgery or on admission, identify carriers during an outbreak, and detect pertussis and respiratory viruses.

A sterile swab is rubbed against the target mucosa to collect organisms and cells, placed into transport medium, and plated onto selective media. Growth is identified and, when clinically relevant, tested for antibiotic susceptibility. Rapid antigen and molecular tests on the same swab give an answer within minutes, but a negative rapid strep test in a child is generally confirmed by culture because missed strep can lead to rheumatic fever.

Do not swab the throat, and do not put a tongue blade or anything else in the mouth, if epiglottitis is suspected. A child who is drooling, sitting forward in a tripod position with stridor, a muffled voice and severe sore throat can develop complete airway obstruction from that stimulation. Keep the child calm, keep the parent present, and get emergency airway support.

Gagging and vomiting are common with throat swabs, and nasopharyngeal swabs cause watering eyes, sneezing and occasionally epistaxis. The genuine danger is precipitating airway obstruction in unrecognized epiglottitis.

Recent antibiotics, antiseptic gargles or throat lozenges suppress growth. Swabbing the tongue, cheeks, uvula or teeth instead of the tonsils and posterior pharynx, or letting the swab touch the tongue on the way out, contaminates the specimen with oral flora. Recent nasal sprays, antibiotic ointment or saline irrigation before a nasal screen lowers yield. A dried-out swab, the wrong transport medium and delayed transport all reduce recovery.

Collect before antibiotics are started and ask about any recent antibiotic or antiseptic gargle use. Collect before meals, or well after, to reduce vomiting. Have suction, tissues and an emesis basin within reach. Wear a mask and eye protection. Set up good lighting and a tongue blade. Explain to the patient or parent that the swab causes a brief gag but is over in seconds, and for a child, position on a parent's lap with gentle secure holding.

For a throat culture, depress the tongue, have the patient open wide and say 'ahh' to lift the soft palate, and swab both tonsils and tonsillar pillars and the posterior pharyngeal wall with firm rubbing, deliberately touching any exudate, membrane or ulcer, while avoiding the tongue, teeth, cheeks and lips. For an anterior nasal screen, insert the swab about one to two centimeters into each naris and rotate against the mucosa. For a nasopharyngeal specimen, pass the swab straight back along the floor of the nose to the nasopharynx and leave it in place several seconds before withdrawing. Place the swab in the correct transport tube at once and label with the exact site.

Offer water, tissues and oral care once collection is complete. Transport promptly. Institute the appropriate isolation precautions while results are pending if pertussis, diphtheria or a resistant organism is suspected. Teach that untreated streptococcal pharyngitis can lead to acute rheumatic fever and poststreptococcal glomerulonephritis, so the full antibiotic course must be completed even after the sore throat resolves.

Growth of group A streptococcus confirms strep throat and the need for antibiotics primarily to prevent rheumatic fever. A positive nasal MRSA screen indicates colonization, which may trigger decolonization before surgery and contact precautions. Because normal flora is expected in these sites, other growth is interpreted against the clinical picture rather than treated automatically.

Never put a swab or a tongue blade into the mouth of a child you suspect has epiglottitis; protect the airway and summon help first, because the examination itself can cause complete obstruction.

No growth of Mycobacterium species after the full incubation period, commonly six to eight weeks.

Culture is the definitive test for tuberculosis. It confirms what a smear only suggested, identifies the exact species so that Mycobacterium tuberculosis complex is separated from nontuberculous mycobacteria, and supplies the isolate for drug susceptibility testing, which is the only way multidrug-resistant tuberculosis is identified. It is also used to document conversion to negative during treatment.

The specimen, most often sputum but also gastric aspirate in young children, bronchial washings, urine, cerebrospinal fluid, pleural or other body fluid, or tissue, is decontaminated to suppress ordinary bacteria and then inoculated into liquid and onto solid media. Mycobacteria divide very slowly, so liquid systems take days to weeks and solid media longer. A nucleic acid amplification test run in parallel can confirm M. tuberculosis and detect rifampin resistance within hours, long before the culture matures.

There is no direct risk to the patient from the culture. Sputum induction and bronchoscopy are aerosol-generating and pose real transmission risk to staff and other patients. Gastric aspiration in a child requires nasogastric tube placement and is uncomfortable and distressing.

Antituberculous drugs started before collection reduce recovery, so collect first. A saliva specimen rather than true sputum, or too small a volume, lowers yield. Delay at room temperature allows ordinary bacteria to overgrow and the decontamination step then kills the mycobacteria along with them. Rinsing the container or the patient's mouth with tap water can introduce environmental mycobacteria and cause a false positive.

Place the patient in airborne isolation in a negative-pressure room and wear a fit-tested N95 or higher respirator. Collect the number of specimens required by protocol, classically three, on separate days and in the early morning. In young children who swallow their sputum, gastric aspirates are collected on waking, before the child gets out of bed or eats, because you are sampling secretions swallowed overnight. Have the patient rinse the mouth with plain water only and never rinse the container with tap water. Collect before anti-tuberculous therapy begins.

Keep the patient in the negative-pressure room, or for an outpatient use a collection booth or an outdoor area away from others. Coach deep breathing and a hard cough into a sterile leakproof container. Keep out of the cough plume and keep your respirator on. Label with the date, time and exact source, since the laboratory processes different sources differently.

Transport promptly and refrigerate if delayed. Maintain airborne precautions until the provider discontinues them based on treatment, clinical improvement and serial negative smears. Teach the patient to cover coughs and to wear a surgical mask when leaving the room. Above all, teach that treatment is multiple drugs for many months and must be completed, and support directly observed therapy if that is the plan. Expect mandatory reporting to public health and a contact investigation of household and close contacts.

Growth of M. tuberculosis complex confirms active tuberculosis, and the susceptibility panel determines the regimen. Resistance to both isoniazid and rifampin defines multidrug-resistant tuberculosis and changes the drugs, the duration and the isolation period entirely. Growth of a nontuberculous mycobacterium such as Mycobacterium avium complex is a different disease with a different regimen and is not spread person to person.

Isolation is driven by suspicion, not by confirmation: put the patient in airborne precautions the moment tuberculosis is considered, because the culture will not answer for weeks.

No growth, or skin flora in amounts consistent with colonization rather than infection.

Ordered to identify the organism causing an infected surgical site, pressure injury, diabetic foot ulcer, abscess, bite wound, burn or cellulitis with drainage, and to determine which antibiotic will work. It also helps distinguish colonization, which every open wound has, from true infection, and it detects resistant organisms such as MRSA, VRE and multidrug-resistant gram negatives that change both therapy and isolation.

Material is obtained by aspirating pus with a needle and syringe, by taking a piece of viable tissue, or by swabbing, and that is the order of preference, because aspirate and tissue reflect the true pathogen while a surface swab mostly grows whatever is colonizing the surface. Aerobic and anaerobic cultures are set up, organisms are identified, and susceptibility testing follows. A Gram stain gives an early answer within hours.

Pain during cleansing and sampling, bleeding, and the possibility of driving surface organisms deeper if the wound is not cleaned first. Needle aspiration carries a small risk of injuring adjacent structures.

Antibiotics started before collection suppress growth. Swabbing pus, slough, eschar or the old dressing rather than viable tissue at the wound base is the classic error and grows contaminants instead of pathogens. Cleaning with antiseptic immediately before swabbing kills the organisms you are trying to culture. Failing to send an anaerobic specimen, or leaving an anaerobic sample exposed to air, loses the anaerobes entirely. Delayed transport reduces recovery of fastidious organisms.

Collect before the first antibiotic dose whenever the patient's condition allows. Gather sterile supplies and the correct aerobic and anaerobic transport devices before you start. Premedicate for pain about thirty minutes ahead if the wound is painful. Use hand hygiene and clean gloves to remove the old dressing, then change to sterile gloves for collection. Irrigate and cleanse the wound with sterile normal saline first and debride loose slough if that has been ordered; never apply antiseptic right before culturing.

If there is pus, aspirate it with a syringe, which is the best specimen. If tissue can be taken, take tissue. If you must swab, use the Levine technique: rotate the swab over about one square centimeter of clean, viable tissue at the wound base with enough pressure to express fluid from within the tissue, avoiding the wound edges, eschar and surface exudate. Place the anaerobic specimen into its transport medium immediately. Label with the exact site, the depth, and whether the specimen is superficial or deep.

Apply the ordered dressing and transport the specimen promptly at room temperature. Document a full wound assessment including length, width, depth, undermining or tunneling, tissue type in the wound bed, amount and character of exudate, odor, periwound skin, and any systemic signs. Give the ordered antibiotic once the specimen is obtained. Institute contact precautions if a resistant organism is identified. Monitor for spreading erythema, increasing pain, fever, tachycardia and other signs of progressing infection or sepsis.

Growth of a pathogen together with clinical signs of infection indicates true infection requiring systemic therapy. MRSA, VRE, Pseudomonas and extended-spectrum beta-lactamase producers drive both drug selection and isolation. Anaerobes or mixed polymicrobial growth suggest a deep or necrotizing process. Mixed growth from a superficial swab in a wound without clinical signs of infection usually reflects colonization and does not by itself justify antibiotics.

Culture clean viable tissue and not pus or slough, and obtain it before the antibiotic; and treat rapidly spreading pain, erythema, crepitus, bullae or pain out of proportion to the wound as possible necrotizing infection, which is a surgical emergency and cannot wait for the culture.

Negative: no Zika virus RNA detected and no Zika IgM antibody.

Tested in symptomatic people with fever, maculopapular rash, joint pain and conjunctivitis after travel to an area with Zika transmission or sexual exposure to a traveler, in pregnant women with possible exposure because of the risk to the fetus, and in infants born with microcephaly, intracranial calcifications or other findings suggesting congenital Zika syndrome.

Nucleic acid amplification testing detects viral RNA in serum and urine but only during the brief viremic window, roughly the first two weeks after symptom onset, with urine often remaining positive slightly longer than serum. IgM antibody testing covers the later window, but it cross-reacts with dengue and other flaviviruses, so a positive or equivocal IgM usually requires confirmatory neutralizing antibody testing.

None beyond routine venipuncture. The significant burden is psychological, particularly for a pregnant woman awaiting a result that concerns her fetus.

Timing determines everything. Testing too late produces a false negative nucleic acid test, and testing too early produces a false negative IgM because antibody has not yet developed. Cross-reactivity with dengue, West Nile, yellow fever and prior flavivirus vaccination confuses serology. Collecting only serum when urine is also indicated, or improper storage, reduces detection.

Take a detailed travel history for the patient and for sexual partners, and establish the exact date of symptom onset, because that date determines which test is valid. Confirm pregnancy status. Collect both serum and urine when the protocol calls for it. Begin teaching mosquito bite prevention at this visit rather than waiting for a result.

Perform routine venipuncture and obtain a clean-catch urine specimen. Label with the date of symptom onset and the date of travel or exposure, since the laboratory needs these to interpret the result.

Report the case as required by public health authorities. Counsel on preventing sexual transmission using condoms or abstinence for the interval recommended for the patient's sex and pregnancy status. Teach mosquito bite prevention with repellent, long sleeves, screens and removal of standing water, emphasizing the first week of illness when the patient is viremic and can seed local mosquitoes. Arrange serial fetal ultrasound and specialist follow-up for a pregnant patient, and pediatric evaluation including hearing and eye examination for an exposed newborn.

A positive nucleic acid test confirms current infection. A positive IgM suggests recent flavivirus infection and needs confirmation before it is acted on. In pregnancy, confirmed infection prompts serial ultrasound surveillance for microcephaly, intracranial calcifications and growth restriction, plus evaluation of the newborn. Zika is also associated with Guillain-Barre syndrome, so new ascending weakness after a Zika-like illness requires immediate evaluation.

The date of symptom onset determines which Zika test is valid, so document it, and never reassure a pregnant patient on the basis of a specimen drawn outside its diagnostic window.