A case of accessory mammary cancer in a male patient and a literature review.

A 68-year-old Chinese male patient was referred to the present hospital because of a right axillary lump in May 2011. Physical examination showed a rigid movable mass measuring 35 mm in diameter in the right axilla. No mass was palpable in either breast. Mammograms were normal. Physical and imaging examination of the head and neck region, lung, and upper and lower gastrointestinal tract also revealed no evidence of a primary tumor. Ultrasonography and resonance imaging (MRI) revealed no evidence of tumors in the bilateral mammary glands. Fine needle histological biopsy for suspected malignancy was performed, and the patient underwent tumor resection with axillary lymph node dissection on Jun 2011. Moderately differentiated adenocarcinoma in ectopic breast tissue was diagnosed based on the pathologic result, the tumor was immunohistochemically positive for ER, PR, and HER-2.