Cutaneous Sweat Gland Carcinomas with Basaloid Differentiation: An Update with Emphasis on Differential Diagnoses.

This article focuses on primary cutaneous sweat gland carcinomas with basaloid differentiation, including cribriform apocrine carcinoma, endocrine mucin-producing sweat gland carcinoma, mucinous carcinoma, adenoid cystic carcinoma, spiradenocarcinoma, and digital papillary adenocarcinoma. These tumors are rare and pose a significant diagnostic challenge. Their clinical presentation is nonspecific and there is significant overlap of their histologic features. Confident diagnosis is necessary because their clinical behavior ranges from indolent, nonrecurring, nonmetastasizing tumors to those with potential for disseminated disease and mortality. They should be separated from cutaneous metastases of primary visceral adenocarcinomas. Salient features of these rare entities are discussed with emphasis on distinguishing features and diagnostic clues.