Primary carcinoma of ectopic breast tissue in axilla.

A 30 years old married lady presented with 4 x 5 cm, firm, non-tender, mobile swelling on anterior wall of left axilla. FNAC revealed carcinoma. The examination of breast including axillary tail, arm, chest and abdomen did not reveal any abnormality. Mammogram and MRI of both breasts did not reveal any lesion in the breast including axillary tail. Local wide excision along with axillary clearance was carried out. Final histopathology revealed invasive ductal carcinoma (Grade II) of axillary breast tissue and one, out of the recovered lymph nodes, was involved by the tumour. The immunohistochemistry also confirmed the findings.