Cancer — Integumentary System (Skin Cancer) — Precision Clinical Education

Pathophysiology

Basal cell carcinoma (BCC): Most common (80%). Slow-growing, rarely metastasizes but can invade deep into local bone, nerves, and vessels. Sometimes called "rodent ulcer"
Squamous cell carcinoma (SCC): Second most common. More aggressive than BCC with significant risk of spreading to regional lymph nodes. Actinic keratosis is a precursor
Malignant melanoma: Most fatal form. Metastasizes readily to bones, liver, lungs, and CNS
Epithelial cells are "labile" (programmed for rapid replacement), making them particularly vulnerable to UV-induced DNA damage
Lentigo maligna (Hutchinson freckle): Slowly progressive preneoplastic disorder that can take up to 20 years to evolve into invasive melanoma
Primary risk factor: excessive UV radiation (sunlight or tanning beds). Fair-skinned individuals most affected

ABCDE mnemonic for melanoma: Asymmetry. Irregular Borders. Varied Colors. Diameter >6 mm. Evolving shape/size
Non-healing sore: A sore that comes and goes or never fully heals (most dependable sign of non-melanoma skin cancer)
"Ugly Duckling" principle: A mole that looks significantly different from others on the body
BCC: Lumps with pink pearly edges and soft sunken middle
SCC: Scaly or crusted surface
Enlarged, firm, nontender, fixed lymph nodes (potential metastasis)

Any lesion meeting ABCDE criteria: Immediate dermatology referral
Non-healing sore that recurs or persists: Most reliable indicator of BCC or SCC
Rapidly changing mole or "Ugly Duckling" lesion: Potential melanoma — urgent referral
Bleeding, ulcerating, or crusting lesion: Do not massage. Document and refer
Fixed regional lymph nodes: Indicates potential metastatic spread from primary skin cancer

Local contraindication: Strictly contraindicated over any undiagnosed skin lesion, active tumor site, or recent radiation site
Melanoma precaution: Techniques that aggressively increase lymphatic or venous flow should be avoided for melanoma patients
Lymphedema warning: Lymph node removal or irradiation for staging creates lifelong risk of protein-rich fluid accumulation
Radiation-induced sensitivity: Radiation leaves skin thin, red, and irritated at entry and exit sites. Avoid these areas (see radiation-therapy)
Analgesic masking: Cancer patients on strong analgesics may have reduced pain sensitivity
Therapist role: Document and refer any suspicious lesion professionally. Do not alarm the client but do not ignore findings
Not contagious: Skin cancer is not infectious — standard hygiene only

Know the ABCDE mnemonic for melanoma identification
Know the "Ugly Duckling" principle as a clinical heuristic for suspicious lesions
A non-healing sore is the most dependable sign of non-melanoma skin cancer
Distinguish BCC (pink pearly edges, sunken middle) from SCC (scaly, crusted)
MTs are uniquely positioned to observe lesions clients cannot see (back, posterior legs, scalp)

Skin cancer is the most common cancer. BCC is most common, SCC is more aggressive, melanoma is most fatal
The ABCDE mnemonic and "Ugly Duckling" principle are essential screening tools. A non-healing sore is the most dependable sign of BCC/SCC
Local massage is strictly contraindicated over undiagnosed lesions, active tumor sites, and recent radiation areas
Melanoma metastasizes readily to bones, liver, lungs, and CNS. Aggressive lymphatic techniques should be avoided
MTs are uniquely positioned to observe suspicious skin changes and should document and refer