Medullary breast carcinoma (MBC) is a uncommon variant of invasive ductal carcinoma of breast. It accounts for 4% of all invasive breast cancers and is a frequent phenotype of BRCA 1 hereditary breast cancer. Last five years of our hospital records show only one case of medullary breast carcinoma. Despite of its aggressive histopathological features, it has good prognosis. We report a 38 year female who presented to our hospital with a single, large, well circumscribed lump in the upper outer quadrant of right breast since 3 months. Mammography showed multiple asymmetric densities in upper outer quadrant of right breast. Trucut biopsy report was suggestive of high grade duct carcinoma. She underwent Modified Radical Mastectomy of right breast along with Chemotherapy and Radiotherapy. During 36 month month of follow-up, patient is free of disease. Histopathological report was suggestive of Medullary breast carcinoma. Molecular subtype was Her-2 type i.e: Her-2 neu positive and negative Estrogen receptor (ER) & Progesterone receptor (PR).

Keywords : Breast lump, Immunohistochemistry, : Medullary Breast Carcinoma