Medullary breast carcinoma is a rare type of breast cancer that often can be treated successfully. It is marked by lymphocytes (a type of white blood cell) in and around the tumor that can be seen when viewed under a microscope.
This is the only breast cancer associated with a loss of function mutation in BRCA1, and thus the only form associated with a hereditary mutation. It is typically triple-negative and exhibits upregulation of p53.
This is one of five types of epithelial breast cancer: ductal, lobular, medullary, colloid, and tubular.
DCIS is less commonly present, and medullary breast cancer tends to have a pushing, rather than infiltrative, border. The tumour presents as a soft, fleshy mass with a pushing border. Tumours commonly possess mutations of E-Cadherin, which results in its overexpression. Strengthened adhesions between tumour cells reduce the frequency of metastasis.