Breast Carcinoma Staging
Oncologists have developed an intricate system to stage patients with breast carcinoma. Pathologists need not concern themselves with most of the details, but a few points bear remembering.
T-stage
- pTis: Ductal carcinoma in situ
- pT1mi: Microinvasive carcinoma (all foci less than or equal to 0.1 cm)
- pT1: A carcinoma greater than 0.1 to 2.0 cm in greatest dimension
- pT2: A carcinoma greater than 2.0 to 5.0 cm in greatest dimension
- pT3: A carcinoma greater than 5.0 cm in greatest dimension
- pT4: A carcinoma of any size with direct extension to the chest wall or skin (ulceration or skin nodules)
In the presence of two or more nodules, use the largest dimension of the largest nodule to determine the T-stage.
N-stage
Extent of involvement:
Isolated carcinoma cells: Foci less than 0.2 mm in greatest dimension and/or fewer than 200 carcinoma cells in one tissue section
Micrometastasis: Deposits between 0.2 mm and 0.2 cm in greatest dimension and/or greater than 200 carcinoma cells in one tissue section
Macrometastasis: A focus 0.2 cm or greater in greatest dimension
Classification:
- pN0: All lymph nodes free of carcinoma.
- pN1: 1-3 lymph nodes containing metastatic carcinoma
- pN2: 4-9 axillary lymph nodes containing metastatic carcinoma
- pN3: 10 or more axillary lymph nodes containing metastatic carcinoma
Lymph nodes containing isolated carcinoma cells are considered free of carcinoma for staging purposes.
