Ectopic breast carcinoma.

Carcinoma of the accessory breast tissue (CABT) is an extremely rare occurrence, representing 0.3% of all breast malignancies. A 65-year-old, postmenopausal woman was referred to our Breast Clinic complaining of a palpable, growing, and painful mass in her right axilla. Physical examination revealed a palpable tender mass, approximately 3 cm in size, visibly infiltrating the overlying skin area, while physical examination of the breast revealed no palpable lesions. Core biopsy of the mass was promptly scheduled, and the histological report came back positive for Nottingham Grade II NST invasive carcinoma of the breast. The patient underwent breast-conserving surgery and concomitant axillary lymph node dissection (ALND) for removal of the malignant mass. Care was taken to preserve the axillary vein and the long thoracic nerve. Closure of the axillary incision required mobilization of skin flaps to ensure optimal cosmetic results. Despite the ectopic breast tissue being a largely benign and infrequent occurrence, the breast surgeon must remain vigilant for the possibility of CABT development. At any rate, further epidemiological studies incorporating as many patients as possible are required in order to formulate recommendations on the management and prognosis of CABT. Until such guidelines exist, excision of the carcinoma, along with ALND performance, is a reasonable and justified approach to the surgical treatment of CABT.