Cystic basal cell carcinoma or hidrocytoma? The use of an excisional biopsy in a histopathologically challenging case.

Basal cell carcinoma (BCC) has many histologic variants. These variants may show differentiation toward benign and malignant tumors of cutaneous appendages, especially hair follicles. Herein we describe a lesion that was clinically thought to be a BCC, but a superficial biopsy showed histologic features suggestive of an apocrine hidrocystoma. Because of some cytologic atypia, complete excision was recommended. The excision specimen revealed a cystic BCC. The importance of examining the entire neoplasm before reaching a final pathologic diagnosis is emphasized.