Medullary Carcinoma of the Breast
Definition
- A rare breast carcinoma with a syncitial growth pattern and high grade cytology reported to have a good prognosis
Diagnostic Criteria
- Syncitial growth pattern in at least 75% of tumor
- Cell margins not distinct
- Heavy mononuclear inflammatory infiltrate
- Microscopically circumscribed
- No infiltration
- Absence of neoplastic ducts or glands
- High grade pleomorphic nuclei with prominent nucleoli
- We require all five features to make the diagnosis
- Carcinomas lacking one of these features have been termed "atypical medullary carcinoma" by some
- We do not use that term, diagnosing them instead as infiltrating ductal carcinoma
Richard L Kempson MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting:: May 1, 2006