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Staging (DCIS)
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Staging (DCIS)
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Pathologic Staging (pTNM)
CAP Approved Breast • DCIS 3.2.0.0
TNM Descriptors (required only if applicable) (select all that apply)
___ r (recurrent)
___ y (posttreatment)
Primary Tumor (Invasive Carcinoma) (pT)
___ pTis (DCIS): Ductal carcinoma in situ
___ pTis (Paget): Paget disease of the nipple not associated with invasive
carcinoma and/or carcinoma in situ (DCIS and/or LCIS) in the underlying breast parenchyma.
Note: If there has been a prior core needle biopsy, the pathologic findings from the core, if available, should be incorporated in the T classification. If invasive carcinoma or microinvasion were present on the core, the protocol for invasive carcinomas of the breast should be used and should incorporate this information.
Regional Lymph Nodes (pN) (choose a category if lymph nodes received with the specimen; immunohistochemistry and/or molecular studies are not required)
If internal mammary lymph nodes, infraclavicular nodes (level III axillary), or supraclavicular lymph nodes are included in the specimen, consult the AJCC Cancer Staging Manual for additional lymph node categories.
Modifier (required only if applicable)
___ (sn): Only sentinel node(s) evaluated. If 6 or more nodes (sentinel
or nonsentinel) are removed, this modifier should not be used.
__ (f): Nodal metastasis confirmed by fine needle aspiration or core needle biopsy.
Category (pN)
___ Not applicable
___ pNX: Regional lymph nodes cannot be assessed
___ pN0: No regional lymph node metastasis identified histologically
___ pN0 (i+): ITCs only (malignant cell clusters no larger than 0.2 mm) in regional lymph node(s)
___ pN1mi: Micrometastases (greater than 0.2 mm and/or more than 200 cells, but none greater than 2.0 mm).
___ pN1a: Metastases in 1 to 3 axillary lymph nodes, at least 1 metastasis larger than 2.0 mm##
___ pN1b: Metastases in ipsilateral internal mammary sentinel nodes, excluding ITCs
___ pN1c: pN1a and pN1b combined
___ pN2a: Metastases in 4 to 9 axillary lymph nodes (at least 1 tumor deposit greater than 2.0 mm)##
___ pN2b: Metastases in clinically detected internal mammary lymph nodes with or without microscopic
confirmation; with pathologically negative axillary nodes
___ pN3a: Metastases in 10 or more axillary lymph nodes (at least 1 tumor deposit greater than 2.0 mm)
___ pN3b: pN1a or pN2a in the presence of cN2b (positive internal mammary nodes by imaging); or pN2a in the presence of pN1b
___ pN3c: Metastases in ipsilateral supraclavicular lymph nodes
#Note: Isolated tumor cell clusters (ITC) are defined as small clusters of cells not greater than 0.2 mm or single tumor cells, or a cluster of fewer than 200 cells in a single histologic cross-section.# ITCs may be detected by routine histology or by immunohistochemical (IHC) methods. Nodes containing only ITCs are excluded from the total positive node count for purposes of N classification but should be included in the total number of nodes evaluated.
## Approximately 1000 tumor cells are contained in a 3-dimensional 0.2-mm cluster. Thus, if more than 200 individual tumor cells are identified as single dispersed tumor cells or as a nearly confluent elliptical or spherical focus in a single histologic section of a lymph node, there is a high probability that more than 1000 cells are present in the lymph node. In these situations, the node should be classified as containing a micrometastasis (pN1mi). Cells in different lymph node cross-sections or longitudinal sections or levels of the block are not added together; the 200 cells must be in a single node profile even if the node has been thinly sectioned into multiple slices. It is recognized that there is substantial overlap between the upper limit of the ITC and the lower limit of the micrometastasis categories due to inherent limitations in pathologic nodal evaluation and detection of minimal tumor burden in lymph nodes. Thus, the threshold of 200 cells in a single cross-section is a guideline to help pathologists distinguish between these 2 categories. The pathologist should use judgment regarding whether it is likely that the cluster of cells represents a true micrometastasis or is simply a small group of isolated tumor cells.
Nodes containing only ITCs are excluded from the total positive node count for purposes of N classification but should be included in the total number of nodes evaluated.
Distant Metastasis (pM) (required only if present)
___ pM1: Distant detectable metastasis as histologically proven larger than 0.2 mm
Note: The MX designation has been eliminated from the AJCC/UICC TNM system. Definitions have been modified to exclude clinical information
The presence of distant metastases in a case of DCIS would be very unusual. Additional sampling to identify invasive carcinoma in the breast or additional history to document a prior or synchronous invasive carcinoma is advised in the evaluation of such cases.