Board review: cutaneous oncology essentials
High-yield recognition and pathology concepts for melanoma, basal cell carcinoma and squamous cell carcinoma.
Updated: 2026-09-13
Written for clinicians and medical students
This section is a teaching reference for doctors, residents and medical students. It is not patient guidance and not a substitute for clinical examination, and it must not be used for self treatment.
Recognition
- Use ABCDE and the ugly-duckling sign for melanoma triage, but remember nodular melanoma may be symmetric and should be assessed for elevation, firmness and growth [1].
- Basal cell carcinoma commonly shows pearly translucency, telangiectasia and ulceration. Squamous cell carcinoma is more often keratotic, indurated, tender or rapidly growing [2].
- A changing, bleeding or non-healing lesion needs dermoscopic assessment and biopsy rather than empirical topical treatment.
Pathology and staging pearls
- Breslow thickness is a central prognostic and staging variable in invasive melanoma. Report ulceration, mitotic activity, margins and other required synoptic elements [1].
- High-risk cutaneous squamous cell carcinoma features include poor differentiation, perineural invasion, depth, high-risk site, immunosuppression and recurrence [2].
- Biopsy technique must preserve depth when melanoma is possible; complete excision with a narrow clinical margin is preferred when feasible [1].