[Clinical Experience of a Primary Accessory Breast Cancer Patient].

A 59-year-old woman attended a previous hospital complaining of a nodule of the right axilla. Although ultrasonography had shown no evidenceof malignancy, a growth of thenodulewas found on follow-up. Excisional biopsy revealed a primary accessory breast cancer. Because the resected margins were involved, she was referred to our hospital for additional treatment. Based on imaging, both bilateral mammary glands and axillary lymph nodes were reported normal, and distant metastasis was not observed. We performed additional resection of the right axillary tissue around the biopsy site and the right axillary lymph nodedisse ction. Histo-pathological examination revealed the residual invasive ductal carcinoma in the resected specimen. Both the new surgical margins and the lymph nodes were free of disease. Accessory breast cancer is relatively rare, with the incidence being less than 1% of all breast cancers. It is most frequent in the axillary region. Local extensive resection with sufficient surgical margin and axillary lymph node dissection are generally required. This case report presents our clinical experience of accessory breast cancer with some discussion of the literature.