Track

Case Reports

Abstract

Case: A 28-year-old male presented to general surgery with a 10-year history of a slowly enlarging left axillary mass associated with numbness when the arm was raised above the head. X-ray and ultrasound were non-diagnostic. Six months later, a CT scan showed ill-defined skin thickening suspicious for hidradenitis suppurativa. The patient was sent to dermatology, where he was thought to have a ruptured cyst and underwent an unsuccessful trial of intralesional corticosteroid injection. After the lesion failed to respond, a punch biopsy was performed and showed eccrine glands associated with fibrosis. Consideration was given to a scar or fibromatosis, although an immunohistochemical stain for beta-catenin was negative. Incisional biopsy showed similar findings with one focus of atypia and perineural invasion concerning for microcystic adnexal carcinoma. Wide local excision revealed a 2.8 cm in diameter tumor with a positive deep margin overlying the intercostobrachial nerve, which provides sensation to the arm.  

Discussion: Microcystic adnexal carcinoma (MAC) classically presents as a solitary lesion in the head and neck region of older individuals. Histologic diagnosis on a small biopsy can be difficult, as can management given the propensity for local recurrence and potential neurological morbidities of surgery. We present this extraordinary case as an example of a prolonged time to the initial diagnosis of cancer in a young patient and to increase awareness of this possible unusual presentation of MAC as an ill-defined axillary mass.