Microcystic Adnexal Carcinoma: A Rare and Locally Aggressive Adnexal Neoplasm

Microcystic adnexal carcinoma (MAC) is a rare, locally aggressive cutaneous neoplasm with a high potential for local recurrence. It primarily affects the head and neck region and is thought to arise from pluripotent adnexal keratinocytes. The tumor is characterized by slow, progressive growth. A 70-year-old man presented with a lesion in the right supraorbital region, consisting of an irregular, yellowish, firm, and poorly defined plaque. A punch biopsy revealed an infiltrative neoplasm composed of nests and cords of atypical basaloid cells. The patient underwent Mohs micrographic surgery followed by reconstruction using an advancement flap incorporating superior and inferior Burow's triangles. The postoperative course was uneventful, with no evidence of recurrence after six months of follow-up. MAC is a rare cutaneous neoplasm that is frequently underdiagnosed and has a high risk of local recurrence if not completely excised. Mohs micrographic surgery is the treatment of choice because it allows complete margin assessment while maximizing tissue preservation.