Primary cutaneous apocrine carcinoma, arising in tubular apocrine adenoma

Primary cutaneous apocrine carcinoma is a rare adnexal tumor that arises from apocrine progenitor cells. These tumors may be associated with benign apocrine hyperplasia, and a longstanding history of a lesion should not preclude a malignant diagnosis. We report a case of a 70-year-old female who presented to the clinic with a 3-year history of an asymptomatic vulvar lesion. An excisional biopsy was performed. Histopathologic examination revealed a tumor with two distinct components. The first component was determined to be a benign tubular apocrine adenoma. The second component, arising within the apocrine adenoma, was determined to be an apocrine carcinoma based on histopathologic features and immunohistochemical profile. Twelve months after subsequent wide local excision and sentinel node biopsy, the patient is alive without recurrence.