Microcystic adnexal carcinoma

Abstract

Microcystic adnexal carcinoma (MAC) is a rare adnexal tumor often found on the head and neck and usually presenting as an ill-defined, yellowish, or faintly erythematous plaque. It is characterized by aggressive local infiltration and has a high propensity for perineural invasion (PNI). Most cases have been reported in white patients aged 40-60 years, and there is no sexual predilection. The tumor also occurs in other ethnic groups and across a much wider age range. An adequately sized biopsy is necessary for diagnosis. Surgery is the treatment of choice. The poorly defined clinical margins and propensity for perineural spread make Mohs micrographic surgery (MMS) preferable to standard surgical excision. When nerve involvement is present, MMS with formalin-fixed, paraffin-embedded sections should be considered. The prognosis is good, and the 10-year survival rate is higher than 85%. Metastases are rare.