Invasive Ductal Carcinoma Arising from Ectopic Breast Tissue in Axilla: A Case Report

Abstract

Primary carcinoma of ectopic breast tissue is rare. We present a 57-year-old female patient with a large erythematous bulging mass in the right axilla. Imaging studies did not reveal any other lesions except for the one detected in the right axilla. Wide excision with axillary lymph node dissection was performed. The pathology report revealed a poorly differentiated carcinoma with no surrounding lymphoid tissue or lymphovascular infiltration or noncancerous breast tissue. We think that in our case the tumor was probably derived from a primary carcinoma of ectopic breast tissue rather than from a metastatic tumor or occult breast cancer. One year later, the patient presented with a local recurrence at the ipsilateral breast. Mastectomy with chemotherapy was performed. After three cycles of chemotherapy, imaging studies revealed distant metastases. This case report and literature review describe the characteristics of ectopic breast cancer in the axilla and reflects on which initial management strategy is appropriate.