Epidemiology: > 700,000 new cases/ y in US; 0.3– 16% risk of metastic disease; incidence est 32– 270/ 100,000 annually (no nat’l cancer registry); most pts > 50 y
Morphology: Eroded, friable, hyperkeratotic papules, plaques, nodules; pain can = perineural invasion (↑ risk)
Distribution: Usually photodistributed; forearms/ dorsum of hands most common
High-risk lesions: (1) Histopathology: tumor thickness > 2 mm, perineural invasion; (2) Clinical location: lips, genitals, ear; immunosuppression; recurrent tumors
Diagnosis: Shave bx (must get lesion base) or punch bx
Treatment: Low-risk lesions on the trunk, extremities → excision; lesions on head/ neck over 2 cm → Mohs micrographic surgery (tissue preserving, margin-controlled, cutaneous surgery achieved using local anesthesia), XRT considered for poor surgical candidates or for debunking.