Microcystic adnexal carcinoma - Forty-eight cases, their treatment, and their outcome

Background: Microcystic adnexal carcinoma, or sclerosing sweat duct carcino ma, is an uncommon cutaneous neoplasm associated with extensive local invas ion. The standard of care with regard to the best excisional method in trea ting microcystic adnexal carcinoma has not been established. Objectives: To perform a retrospective study comparing patients treated by Mohs micrographic surgery with those treated by wide excision and to elucid ate the epidemiological features of microcystic adnexal carcinoma. Patients and Methods: A retrospective analysis of a case series involving 4 8 primary and referral patients diagnosed as having microcystic adnexal car cinoma using standardized criteria. All cases were reviewed by the same der matopathologists. Results: Microcystic adnexal carcinoma predominantly affects the left side of the face of middle-aged women. Microcystic adnexal carcinoma is misdiagn osed 30% of the time. The recurrence rate is 1.98% per patient-year. Mohs m icrographic surgery and simple excision show comparable complication rates. Clear margins were obtained in fewer procedures and, therefore, fewer offi ce visits when the lesions were treated with micrographic surgery. The defe ct surface area after full extirpation following Mohs micrographic surgery was a mean of 4 times that of the clinically apparent size. The wide range of difference between the pre- and the post-Mohs micrographic surgery surfa ce area noted in our data indicates that a margin cannot be safely predicte d. Conclusions: Microcystic adnexal carcinoma is a predominantly left-sided, l ocally aggressive facial tumor, which results in significant morbidity. Our data do not support the use of standardized predictable margins. Mohs micr ographic surgery is a reasonable initial treatment, as it accomplishes cure in fewer office visits and does not rely on predicted margins.