Digital Atlas of Breast Pathology by Meenakshi Singh, MD © - Department of Pathology, Stony Brook University Medical Center

Medullary carcinoma: syncytial appearance.
Medullary carcinoma is typically well circumscribed, with high nuclear grade and mitotic rate. DCIS is not commonly associated and most (90%) are ERPR negative. Medullary carcinoma may have a better prognosis.