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SEER Inquiry System - Report
Produced: 09/21/2026 11:38 PM
Question 20180045
Inquiry Details
References:
#1: Solid Tumor Rules. Breast Cancer
#2: CAP Protocol, Breast. Posting date: January 2016
Question:
Solid Tumor Rules (2018)/Histology--Breast: The Histology Coding Instructions for breast cancer indicate the term type is not used to code histology unless documented to be greater than or equal to 90% of the tumor. Does this also apply if the format of pathology reports submitted in the College of American Pathologists (CAP) protocol from a specific facility always describes the histology under the heading, Histologic type: ___? See Discussion.
Discussion:
For certain facilities in our area, the breast pathology reports using a CAP protocol format are formatted as follows; the Final Diagnosis will state Infiltrating carcinoma with the following features. The features list the specific tumor characteristics required in the CAP protocol formatting. The histology is always displayed in the list form and specified as Histologic type: (for example, Histologic type: Ductal carcinoma). Is this specific histology really to be ignored because it is preceded by the word type even if this is just a consequence of the pathology report formatting?
Answer:
In the CAP protocol, the term Histologic Type is a label where the histology that corresponds to the largest carcinoma is collected. According to the CAP protocol for invasive breast cancer, the histologic type corresponds to the largest carcinoma. If there are smaller carcinomas of a different type, this information should be included under "Additional Pathologic Findings." The findings noted in the Final Diagnosis, Histologic Type, and Additional Path Findings of the protocol should be used to determine the histology.
When there are multiple histologies and
1) the subtype or variant is listed as 90% when there is a Not Otherwise Specified/No Specific Type (NOS/NST) and a subtype, or
2) the subtype/variant histology reflects the majority of the tumor when there are two or more different histologies (two or more distinct subtypes)
Code the subtype/variant; otherwise, use the Specific and Not Otherwise Specified/No Specific Type (NOS/NST) Terms and Code listed in Table 2 (columns 1 and 2) of the 2018 Solid Tumor Rules for Breast Cancer.
