Locally advanced triple negative breast cancer arising from fibroadenoma with complete response to neoadjuvant chemotherapy: A case report

•Breast cancer arising in association with a fibroadenoma (FA) is rare and usually early-stage.•We report a rare case of an advanced triple negative breast cancer, with lymph node metastases, within a long-standing FA.•Pathological complete response was achieved after neoadjuvant chemotherapy, as proven on mastectomy with axillary clearance.