Eyelid microcystic adnexal carcinoma.

Microcystic adnexal carcinoma is an uncommon cutaneous tumor with multiple synonyms. On cursory microscopic examination, the tumor mimics syringoma and other benign skin adnexal tumors. However, the asymmetric, infiltrative growth pattern clearly sets the lesion apart as carcinoma. The tumor is locally aggressive, with recurrences common, but regional metastases are rare. Histogenesis is controversial. Optimal treatment consists of complete surgical excision with clear surgical margins.