Clinical course, risk factors, and treatment of microcystic adnexal carcinoma: a short series report.

BACKGROUND: Microcystic adnexal carcinoma (MAC) is a locally aggressive neoplasm of both eccrine and follicular differentiation; it commonly presents on the head and neck of white middle-aged to older patients.

OBJECTIVE: To review the course, risk factors, and management of 10 patients with microcystic adnexal carcinoma (MAC) and to compare treatment outcome by either Mohs micrographic surgery or standard surgical excision.

METHODS: Tumor registry databases were used to identify cases at Roswell Park Cancer Institute in Buffalo, New York. Fifteen cases that were coded as MAC were reviewed. Ten cases were subsequently confirmed to be MAC. From these cases, data were collected on patient demographics, tumor location and size, risk exposure, metastasis, treatment, and recurrence of tumors.

RESULTS: The average age of the patients was 63.4, and females outnumbered males seven to three. Nine tumors were located on the head and neck area. Five patients had a history of radiation therapy, and two patients were sisters. The first-time procedure was Mohs micrographic surgery in four cases and surgical excision in six cases. Three patients in the surgical excision group needed a second procedure, two of whom thereafter underwent Mohs micrographic surgery. In the Mohs micrographic surgery group, none of the patients required a second procedure, and all of the patients were disease free at an average of 23.3 months. One recurrence was noted in the surgical excision group, and the average follow-up was 32 months.

CONCLUSION: This report supports the use of Mohs micrographic surgery for tumor control with the least possible procedures. Risk factors appear to include radiation treatment, ultraviolet exposure, and possibly genetics.