Microcystic Adnexal Carcinoma: Mohs Micrographic Surgery as the Treatment of Choice

Introduction and objectives Microcystic adnexal carcinoma is a rare and aggressive tumor that manifests clinically as a subcutaneous nodule located on the head or neck. The tumor can be confused clinically and histologically with other benign and malignant skin lesions, often leading to inappropriate initial treatment. The chief concern with microcystic adnexal carcinoma is the elevated morbidity and the high rate of recurrence after wide local excision. Recent preliminary studies point to higher cure rates with Mohs micrographic surgery. Material and methods We reviewed the medical histories of 6 consecutive patients with microcystic adnexal carcinoma who underwent Mohs micrographic surgery in our dermatology department between 1995 and 2007. Results In all cases, lesions were located on the head and were primary tumors. Seventy percent of the tumors were wrongly diagnosed initially as basal cell carcinoma. Perineural invasion was not detected in any patient, and all were free of recurrence after between 1 and 12 years of postoperative follow-up. Conclusions The absence of perineural involvement and substantial cell atypia can be attributed to the lesions being primary tumors. This would provide a rationale for definitive radical treatment of the primary tumor from the outset to avoid the complications associated with recurrence. The site and the absence of recurrence in all our patients who underwent Mohs micrographic surgery support the use of this technique as the treatment of choice in microcystic adnexal carcinoma.