A case of microcystic adnexal carcinoma on the back of the head and discussion about the surgical margins

Abstract

A 75-year-old woman was referred to our hospital for the treatment of the mass in the occipital region which had been noticed nearly 10 years ago. Microscopic examination revealed the tumor invasion throughout the dermis and subcutaneous tissue with fibrosis. In the upper dermis, small cysts with horny substance were observed, and tumor strands with eccrine sweat gland differentiation and small nests were detected in the lower dermis. It was diagnosed with Microcystic Adnexal Carcinoma (MAC). The tumor was excised with 20 mm tumor-free-margin including a part of trapezius muscle and skull periosteum. After confirming the negative margin, the defect was covered with a free anterolateral thigh flap. At 6 months after the operation, no recurrence has occurred.[Skin Cancer (Japan) 2017 ; 32 : 211-215]