Nursing Field Notes / Skin & Wound · Skin Cancer · Pathophysiology Course
Skin Cancer ☀️
Basal cell · Squamous cell · Melanoma — and the ABCDE that catches the deadly one
NG-204
INTEGUMENTARY · ONCOLOGY
ADHD-friendly visual edition
Skin cancer is uncontrolled growth of skin cells after their DNA has been damaged — nearly always by ultraviolet light. Which cell mutates decides which cancer you get: the basal layer → basal cell carcinoma, the keratinocytes above it → squamous cell carcinoma, the melanocytes → melanoma. The layers are drawn on NG-051; this page shows what happens when each one goes wrong.
📄 Simple Nursing original — opens in Drive →
🔤 A B C D EAsymmetry · Border irregular · Color varied · Diameter >6 mm · Evolving.
🔬 3 cells, 3 cancersBasal → BCC (most common) · keratinocyte → SCC · melanocyte → melanoma (deadliest).
🚨 Biopsy decidesNothing is diagnosed by looking. Tissue biopsy is definitive.
☀️ SPF 30+, 15 min before, q2hAvoid 10 am–4 pm · never tanning beds · burns happen on cloudy days.
🧨
WHY IT HAPPENS
STEP 1 · CAUSEUltraviolet light breaks DNA. Enough breaks in the wrong genes and the cell stops obeying the "stop dividing" signal.
☀️ UVA vs UVB — how deep the damage goes
UVB is mostly absorbed in the epidermis — it causes sunburn and directly damages keratinocyte and melanocyte DNA. UVA penetrates into the dermis, driving photo-ageing and also contributing to cancer. Tanning beds emit high-intensity UVA and are a recognized carcinogen — a tan is DNA damage made visible.
🧠 UVB = Burn (surface). UVA = Aging (deep). "Broad-spectrum" on the bottle means it covers both.
⚠️ Risk factors — the exam list
☀️UV exposurefrequent sunburns
🛏️Tanning bedsnever safe
👷Outdoor occupationcumulative dose
🧑🦰Fair skinlight skin, blond/red hair, freckles
👪Family historyparent with melanoma
🔵Many moles>50 nevi or atypical nevi
💊Immunosuppressantstransplant & HIV meds
🩹Prior skin canceror chronic wound/scar
👴Older agelifetime UV adds up
☢️Radiation / arsenicoccupational
Darker skin does not mean immunity. Skin cancer is less common in deeply pigmented skin but is more often found late — and it favors the palms, soles, nail beds and mucous membranes, which people don't check.
🧠 "Sun, skin type, moles, meds, mum & dad." Five buckets that cover almost every risk-factor question.
📖 Key terms you get tested on
- Nevus / nevi = mole(s). Melanocytic = made of pigment cells.
- Neoplasm = tumor = a new abnormal growth.
- Benign = stays put, well-defined, grows slowly, doesn't invade. Malignant = invades locally and can metastasise.
- Actinic (solar) keratosis = premalignant rough, dry, "sandpaper" scaly patch on sun-damaged skin — a precursor to squamous cell carcinoma. Treat it.
- Dysplastic / atypical nevus = irregular mole; a marker of increased melanoma risk.
- Metastasis = spread to distant sites via lymph or blood.
- Breslow depth = how many millimeters deep a melanoma has invaded — the strongest prognostic factor.
🧠 BeNign = Be Nice. MALignant = MALicious. Nice growths stay home; malicious ones travel.
🔬
THE THREE TYPES
STEP 2 · WHICH CELL?Find the cell of origin on the cross-section and everything else about the cancer follows.
🔬 Three cells, three cancers — the origin cutaway
🧠 Bottom, middle, pigment. Basal cell starts at the bottom of the epidermis. Squamous starts in the squamous cells above it. Melanoma starts in the melanocytes — and it is the one that digs downward.
👁️ What they look like on the skin
🧠 Pearly = basal. Scaly & crusty = squamous. Multicolored & changing = melanoma. Three words, three cancers.
⭐ The comparison table
| Feature | Basal cell (BCC) | Squamous cell (SCC) | Melanoma |
|---|---|---|---|
| Cell of origin | Basal layer keratinocytes | Keratinocytes above the basal layer | Melanocytes |
| How common | Most common skin cancer | Second most common | Least common of the three |
| How dangerous | Locally destructive; rarely metastasises | Can metastasise — higher risk on the lip, ear, and in immunosuppressed patients | Most deadly; metastasises early and widely |
| Classic look | Pearly/waxy papule, rolled translucent border, telangiectasias, central ulcer that bleeds and re-scabs | Firm, red, scaly, crusted nodule or ulcer; may be tender | Asymmetric, irregular-bordered, multicolored lesion that is changing |
| Where | Sun-exposed: face, nose, inner canthus, ears, head & neck | Sun-exposed: face, ears, lower lip, dorsum of hands; also chronic wounds and scars | Anywhere — including palms, soles, nail beds, scalp, mucosa and the eye |
| Precursor | — | Actinic keratosis | May arise in a pre-existing nevus or appear as a brand-new lesion |
| Typical treatment | Excision, Mohs micrographic surgery (tissue-sparing, used on the face), curettage & electrodesiccation, cryotherapy, topical agents for superficial lesions | Excision or Mohs; radiation in selected cases; treat actinic keratoses early | Wide local excision guided by depth; sentinel lymph node biopsy for staging; immunotherapy/targeted therapy for advanced disease |
🧠 Basal is a bully, squamous is a traveler, melanoma is an assassin. Local damage · sometimes spreads · spreads early and kills.
🧪 Diagnosis — nothing is decided by looking
- Full-body skin examination in good light, including scalp, between toes, soles, nails, genital area — and the "ugly duckling" check: the mole that doesn't look like the patient's other moles.
- Dermoscopy to magnify surface patterns.
- Tissue biopsy is required for definitive diagnosis — but only for lesions that are genuinely suspicious (irregular, uneven, changing). Normal moles are not biopsied.
- For suspected melanoma, a full-thickness (excisional) biopsy is preferred so the pathologist can measure Breslow depth; superficial shave biopsy may under-measure it.
- Sentinel lymph node biopsy stages melanoma; imaging and LDH may be added for advanced disease.
- Photograph and map lesions for comparison over time where policy allows.
🧠 "Suspicious? Sample it." The nurse's job is to notice, describe, document, and escalate — not to reassure.
🚨 Melanoma in darker skin — the pattern that gets missed
- People with darker skin get melanoma less often but die of it more often, largely because it is found late.
- Look at the palms, soles, between the toes, nail beds, mucous membranes and the eyes — not just sun-exposed areas.
- A new, widening, irregular dark band in a nail, especially with pigment spilling onto the surrounding skin (Hutchinson sign), needs referral — not "wait and see."
- Teach sun protection to everyone. Pigment reduces risk; it does not remove it.
🧠 "Check the soles and the nails." The single most useful habit for catching melanoma in patients with darker skin.
🔤
ABCDE — DRAWN OUT
STEP 3 · SCREENFive letters. Benign on the left, suspicious on the right, every time.
🔤 The ABCDE plate — benign vs suspicious, side by side
E is the most important letter. A lesion that is abrupt, sudden or rapidly changing in color, size or shape gets referred even if the other letters look reassuring. Add the "ugly duckling" sign: the mole that looks different from all of that person's other moles.
🧠 Asymmetry · Border · Colour · Diameter · Evolving. Chant it in that order, and remember "Irregular is BAD, and change is worse."
🚨 Other red flags to escalate
- A sore that will not heal, or heals and reopens repeatedly.
- A lesion that bleeds, oozes, crusts or itches without an obvious cause.
- New pain, tenderness or numbness in a mole.
- Redness or swelling extending beyond the border of a mole.
- Spread of pigment from a mole into the surrounding skin.
- A new pigmented lesion in an adult — most moles appear before about age 30.
- Any lesion in a chronic wound, burn scar or old radiation site (Marjolin ulcer → SCC).
🧠 "Won't heal, won't stop bleeding, won't stay the same." Any one of those earns a referral.
✅ How to teach a monthly self-skin exam
- Once a month, in good light, after a bath or shower.
- Use a full-length mirror plus a hand mirror; ask a partner or family member for the back and scalp.
- Work in a fixed order: face → ears → neck → chest → abdomen → arms and hands (including palms, between fingers and nail beds) → back and buttocks → legs → soles and between the toes → scalp (part the hair) → genital area.
- Take photos or draw a body map so change is obvious next month.
- Report anything meeting ABCDE, anything that doesn't heal, or any "ugly duckling."
- High-risk patients should also have regular professional skin checks.
🧠 Same day each month, same order every time. Change is only obvious if you look the same way twice.
☀️
PREVENTION & TEACHING
STEP 4 · TEACHThis is where nursing actually changes the outcome — and it is heavily tested.
☀️ Sun safety, drawn
🧠 "30, 15, 2." SPF 30+, applied 15 minutes before, reapplied every 2 hours (and after water). Three numbers, most of the teaching questions.
👨👩👧 Everything else the patient needs to hear
- Shade and clothing beat sunscreen. Sunscreen is the last line, not the first.
- Infants under 6 months should be kept out of direct sun and covered with clothing/shade; use sunscreen on babies only as advised by their provider.
- Some medicines cause photosensitivity — you burn much faster. Common examples include tetracyclines, sulfonamides, some diuretics, amiodarone, some psychiatric medicines, and isotretinoin (see NG-051). Ask, and teach strict sun protection.
- Radiation-therapy skin and old burn scars stay sun-sensitive for life.
- After any skin-cancer treatment: lifelong surveillance — having one skin cancer is the strongest predictor of the next.
- Address the body-image and anxiety load of facial surgery and repeated biopsies; connect to support.
🧠 "Slip on a shirt, slop on sunscreen, slap on a hat, seek shade, slide on sunglasses." Five S's the patient will actually remember.
🩺 Nursing care around treatment
- Before: confirm consent and site marking, review anticoagulants and allergies, explain what a biopsy or Mohs day actually involves (long day, staged excisions, repeated waiting).
- After a surgical excision: keep the dressing clean and dry per order, watch for bleeding, infection and dehiscence, teach wound care and suture-removal timing — see NG-080.
- Topical chemotherapy (for superficial lesions/actinic keratoses): warn that the treated area is meant to become red, crusted and sore before it heals; apply with gloves, avoid eyes and mucous membranes, and protect from sun.
- Cryotherapy: expect stinging, a blister, then a crust; avoid picking. Pigment change is common.
- Advanced melanoma: immunotherapy and targeted therapies bring their own toxicities (notably immune-related rash, colitis, hepatitis, thyroid and other endocrine effects) — teach patients to report new symptoms early rather than waiting.
- Always: document lesion location, size, appearance and any change, and make sure the referral actually happened.
🧠 The nurse's four verbs on this page: notice · describe · teach · refer.
🗺️ Where this page sits in the set
- NG-051 — Skin: the basal layer, keratinocytes and melanocytes that become these three cancers; plus the lesion vocabulary and assessment technique.
- NG-080 — Wound Care: post-excision wound care, and the chronic wound that can turn into an SCC.
- NG-182 — Dermatitis and NG-225 — Psoriasis: benign inflammatory rashes you must not mistake for cancer — and vice versa. A "patch of eczema" that never clears in one fixed spot deserves a second look.
🧠 One stubborn spot that behaves differently from everything around it is the phrase that should make you look twice — on any page in this set.
⚡
QUICK RECALL
SAY IT OUT LOUD🔤 A·B·C·D·EAsymmetry · Border · Color · Diameter >6 mm · Evolving (the big one).
🔬 Pearly · Scaly · MulticoloredBasal cell · squamous cell · melanoma.
🚨 Melanoma travelsLeast common, most deadly. Depth decides prognosis. Biopsy is definitive.
☀️ 30 · 15 · 2SPF 30+, 15 min before, reapply q2h. Avoid 10–4. Never tanning beds.
🎯 Cover & check — 10 rapid-fire questions
Q1: What do the letters ABCDE stand for?
Asymmetry (halves don't match), Border irregularity (notched, scalloped, blurred), Color variation (mixed brown, tan, black, red, white or blue), Diameter greater than 6 mm (bigger than a pencil eraser), and Evolving — any change in size, shape, color, or new itching or bleeding.
Q2: Which skin cancer is most common, and which is most deadly?
Basal cell carcinoma is the most common. Melanoma is the least common of the three but the most deadly because it metastasises early.
Q3: Describe the classic basal cell carcinoma.
A pearly or waxy, translucent papule with a rolled border, visible fine surface vessels (telangiectasias), and often a central ulcer that scabs, bleeds and never fully heals. Usually on sun-exposed head and neck skin. It is locally destructive but rarely metastasises.
Q4: What is an actinic keratosis and why does it matter?
A rough, dry, sandpapery scaly patch on chronically sun-damaged skin. It is premalignant and can progress to squamous cell carcinoma, so it is treated rather than watched.
Q5: How is skin cancer definitively diagnosed?
By tissue biopsy — but only for lesions that are genuinely suspicious (irregular, uneven, changing). For suspected melanoma a full-thickness excisional biopsy is preferred so the depth (Breslow thickness) can be measured.
Q6: Give the sunscreen teaching in numbers.
Broad-spectrum SPF 30 or higher, applied about 15 minutes before going outside, reapplied every 2 hours and after swimming, towel-drying or heavy sweating. Also avoid sun between 10 am and 4 pm, wear a wide-brimmed hat, long sleeves and UV sunglasses, and never use tanning beds.
Q7: A patient says "It was cloudy, so I didn't need sunscreen." How do you respond?
UV rays pass through clouds, so sunburn absolutely happens on overcast days. UV also reflects off water, snow and sand, which increases exposure. Sun protection is needed any time you are outside during daylight hours.
Q8: Why is melanoma often found later in patients with darker skin?
Because it commonly occurs in places nobody thinks to check — the palms, soles, between the toes, nail beds and mucous membranes (acral lentiginous melanoma) — and because pigment can make lesions harder to identify. A new, widening, irregular dark band in a nail, especially with pigment onto the nail fold (Hutchinson sign), needs referral.
Q9: Which squamous cell carcinomas are most likely to metastasise?
Those on the lower lip and the ear, larger and deeper lesions, recurrent lesions, those arising in chronic wounds, burn scars or radiation sites, and those in immunosuppressed patients such as organ transplant recipients.
Q10: Teach a patient how to do a monthly skin self-exam.
Once a month in good light after a shower, using a full-length mirror and a hand mirror, with help for the back and scalp. Go in the same order every time: face, ears, neck, chest, abdomen, arms and hands including palms, between fingers and nail beds, back and buttocks, legs, soles and between the toes, scalp, and genital area. Take photos or use a body map so change is obvious, and report anything meeting ABCDE, anything that won't heal, or any mole that looks different from all the others.