Medullary Carcinoma of the Breast
Differential Diagnosis
- Infiltrating ductal carcinoma
- We designate simply as infiltrating ductal carcinoma those carcinomas that lack any of the five required diagnostic criteria
- Many of these will be high grade, so the distinction is critical
- We do not make the diagnosis of atypical medullary carcinoma
- Large cell lymphoma
- Lacks syncitial growth pattern and circumscription
- Can simulate medullary carcinoma because of cytology, lymphoid infiltrate and absence of ducts or glands
- Immunohistochemistry for lymphoid antigens and keratin can easily resolve this if it is a problem
