Microcystic Adnexal Carcinoma: Ten Cases Treated by Mohs Micrographic Surgery

BACKGROUND. Microcystic adnexal carcinoma is a slow-growing, nondescript, locally aggressive, deeply infiltrating neoplasm histologically characterized by an infiltrative pattern of basaloid or squamous cells, a desmoplastic stromal reaction, keratin-filled cysts, and glandular structures. OBJECTIVE. Microcystic adnexal carcinoma is uncommon and may be mistaken microscopically for other benign and malignant entities. Perineural or intraneural involvement by tumor cells is characteristic and extension into underlying structures including muscle, fat, and bone are frequently encountered. Although local recurrences are common after standard surgical excision, metastases have not been reported. Extensive resections of lesions may be necessary to extirpate widespread tumor, particularly those that are long standing or recurrent. Because significantly increased morbidity is associated with recurrent disease, surgical and histopathologic techniques that stress examination of all margins are advantageous. METHODS. We review the course of 10 patients with microcystic adnexal carcinoma of the face (six primary and four recurrent lesions) and their treatment by Mohs micrographic surgery.