Medullary carcinomas share a number of features with BRCA-1 associated breast cancers. These features include - relatively young age at diagnosis, lympho-plasmacytic infiltrate, high-grade morphology, triple-negative phenotype, and p53 mutations. Among breast cancers arising in BRCA-1 carriers, about 13% are medullary carcinomas and upto 60% of tumors show some medullary features. Mutations in TP53 are commonly seen in medullary carcinomas. This image is a higher magnification of the previous slide showing highly anaplastic tumor cells in a background of lymphoplasmacytic infiltrate.