Mohs micrographic surgery in the treatment of microcystic adnexal carcinoma.

Microcystic adnexal carcinoma is a rare neoplasm with a propensity for slow growth and extensive local invasion. Pathology is characterized by multiple islands of basaloid epithelial cells, ductal structures, and keratinizing cysts, located intradermally but often extending deep as thin strands of tumor cells intercalating between collagen bundles. Perineural and intramuscular invasion are common. Treatment with Mohs surgery allows for fewer procedures with increased likelihood of long-term cure and tissue conservation.