Borderline phyllodes tumor arising in ectopic breast tissue in the axilla: Report of a rare case with brief review of literature.

Development of a neoplasm in an ectopic breast is uncommon, while the development of phyllodes tumor in an ectopic breast in the axilla is even rarer. We report a rare case of a 51-year-old female who presented with a complain of swelling and pain in the right axilla with no associated complaints in other organs. Magnetic resonance imaging suggested a possibility of metastatic lymphadenopathy. Complete excision of the right axillary mass was performed and sent for histopathological examination which was examined thoroughly and sections were given. On microscopic examination, stromal proliferation in a leaf-like pattern with mild stromal atypia and focal permeation of borders were seen, and a diagnosis of Ectopic borderline phyllodes tumor in axilla was made, which is extremely rare and needs to be differentiated from its close differentials like fibroadenoma and periductal stromal sarcoma.