For Information OnlyBreast
# If tumor is present at the margin of the resection by macroscopic examination, the case is coded as pTX because the total extent of tumor cannot be assessed.
## Paget disease associated with a tumor is classified according to the size of the tumor.
### Microinvasion is extension of cancer cells beyond the basement membrane into adjacent tissues with no focus more than 0.1 cm in greatest dimension. When there are multiple foci of microinvasion, the size of only the largest focus is used to classify the microinvasion (do not use the sum of all the individual foci). The presence of multiple foci should be noted and/or quantified, as with multiple larger invasive carcinomas.
^ Dermal invasion alone (without ulceration, satellite nodules, or inflammatory breast cancer) does not alter T category. Such cases are classified as T1, T2, or T3, depending on tumor size.
^^ Tumor in pectoral muscle should be measured with the breast tumor for determining tumor size and final T category.
^^^ Inflammatory carcinoma of the breast is a clinicopathologic entity characterized by diffuse erythema and edema involving the majority of the skin of the breast, often without an underlying palpable mass. The clinical presentation is due to tumor emboli in dermal lymphatics, although these may not be seen on skin biopsy. The diagnosis is established by the combination of the clinical findings and a biopsy showing cancer, either within dermal lymphatics or in the breast parenchyma. Involvement of dermal lymphatics alone does not indicate inflammatory carcinoma. If the skin biopsy is negative and there is no localized measurable primary cancer, the T category is pTX when pathologically staging a clinical inflammatory carcinoma (T4d). Dimpling of the skin, nipple retraction, or other skin changes, except those in T4b and T4d, may occur in T1, T2, or T3 without affecting the classification.
Regional Lymph Nodes (pN)#
pNXCannot be assessed (previously removed or not removed for pathologic study)
pN0No regional lymph node metastasis histologically, no examination for isolated tumor cells (ITCs)##
pN0(i-)No regional lymph node metastasis histologically, negative morphologic (any morphologic technique, including hematoxylin-eosin and immunohistochemistry) findings for ITCs
pN0(i+)No regional lymph node metastasis histologically, positive morphologic (any morphologic technique, including hematoxylin-eosin and immunohistochemistry) findings for ITCs, no ITC cluster greater than 0.2 mm
pN0(mol-)No regional lymph node metastasis histologically, negative nonmorphologic (molecular) findings for ITCs
pN0(mol+)No regional lymph node metastasis histologically, positive nonmorphologic (molecular) findings for ITCs
pN1Metastasis in 1 to 3 axillary lymph nodes, and/or internal mammary nodes with microscopic disease detected by sentinel lymph node dissection but not clinically apparent###
pN1miMicrometastasis (greater than 0.2 mm, none greater than 2.0 mm)