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SEER Inquiry System - Report
Produced: 03/04/2026 12:25 PM
Question 20240015
Inquiry Details
References:
#1: Solid Tumor Rules. Breast, May 2023 Update
#2: ICD-O-3.2
Question:
Solid Tumor Rules/Histology--Breast: Is ductal carcinoma in situ (DCIS), solid type coded as 8500/2 or 8230/2? See Discussion.
Discussion:
In the NAACCR Coding Pitfalls 2023 webinar, the example of DCIS, solid type is given. The webinar advised us to code 8230/2 (ductal carcinoma in situ, solid type). When going through the beginning of the solid tumor rules in the Changes from 2007 MPH Rules section it states "DCIS/Carcinoma NST in situ has a major classification change. Subtypes/variant, architecture, pattern, and features ARE NOT CODED. The majority of in situ tumors will be coded to DCIS 8500/2." In the equivalent or equal terms section it lists "Type, subtype, variant" can be used interchangeably.
Since the example has it listed as as ductal carcinoma in situ, solid "type," would we code 8500/2 or 8230/2?
Answer:
Assign 8230/2 (ductal carcinoma in situ, solid type/intraductal carcinoma, solid type) using Breast Solid Tumor Rules Table 3 as instructed in Rule H2 for in situ tumors. The carcinoma, NST row lists this histology in the subtype/variant column 3.
Coding histology for in situ breast tumor differs from invasive. While the majority of in situ breast primaries will be coded to DCIS 8500/2, there are others that are listed in Table 3 that should be coded according to the specific histology. Some codes have the word subtype or type as part of their histologic term so these can be coded based on the histologic term as listed in the table. We suggest you routinely review the histology tables to see if a term is listed.
