Carcinoma of the Accessory Axillary Breast: A Diagnostic Dilemma and a Management Challenge

Carcinoma of the accessory axillary breast is uncommon, with an incidence of 0.2 to 0.6%. We report a patient whose biopsy of a suspicious lesion in the axilla present for one year revealed invasive ductal carcinoma (IDC). There was presence of breast tissue and absence of lymphoid tissue in the biopsy, suggesting a breast malignancy. Magnetic resonance mammography was suggestive of the lesion well away from the normal breast, confirming an accessory axillary breast. She was offered wide local excision of the lesion with axillary lymph node dissection and modified radical mastectomy (MRM), and she chose the latter. Her post-operative biopsy showed the involvement of all the 25 lymph nodes harvested. Any suspicious lesion in the axilla should be promptly worked up for malignancy. Accessory axillary breast carcinoma, if confirmed, can be addressed with wide local excision along with axillary lymph node dissection. However, further studies should clarify this and the outcomes.