Pigmented Basal Cell Carcinoma Masquerading as a Melanoma.

Basal cell carcinoma is the most common skin cancer. Pigmented basal cell carcinoma is an uncommon clinical presentation that can resemble a melanoma. We present the clinical and pathologic features of three individuals whose pigmented basal cell carcinomas masqueraded as melanomas. All of the patients were Hispanic and ranged in age from 63 years to 77 years. They presented with a pigmented lesion that was ultimately diagnosed as a pigmented basal cell carcinoma; one woman had a collision tumor consisting of a pigmented basal cell carcinoma and a seborrheic keratosis. All of the patients had their tumors removed using Mohs micrographic surgery, without recurrence. The clinical differential diagnosis of a black tumor-particularly in patients with darker skin types-should include pigmented basal cell carcinoma in addition to melanoma; a biopsy of the lesion will establish the diagnosis.