An official website of the United States government
Home
SEER Inquiry System - Report
Produced: 03/19/2026 3:37 PM
Question 20200069
Inquiry Details
References:
Solid Tumor Rules. Breast
Question:
Solid Tumor Rules (2018)/Histology--Breast: What histology code is used for an in situ encapsulated papillary carcinoma with an invasive carcinoma, NST? See Discussion.
Discussion:
In Table 3 (Specific Histologies, NOS/ NST, and Subtypes/Variants), the entry for papillary carcinoma, NOS includes a change in column 3 of the 2018 Breast Solid Tumor Rules that conflicts with the H Rules. It is not accounted for in the change log. No explanation is offered as to why this change was made. This is a major change because encapsulated papillary carcinoma is frequently associated with carcinoma NST, and we have not been collecting these as such.
Encapsulated papillary carcinoma (8504) in column 3 now includes an indented entry, with invasive carcinoma, NST/invasive duct carcinoma 8504/3. However, most encapsulated papillary carcinomas are in situ or there is no definitive statement of invasive encapsulated papillary carcinoma, so when in situ and invasive tumors are present, we are instructed to code the invasive histology (which would be the invasive carcinoma (NST), 8500/3). How are registrars to arrive at the correct histology without a new H rule or a clarification regarding this update being documented in the change log?
Does the same change/addition apply to solid papillary carcinoma? These are often also associated with carcinoma, NST. Again, without an explanation regarding the change mentioned above, it is difficult to understand why the change was made.
This question was prompted from preparing SEER*Educate coding exercises. We will use the answer as a reference in the rationales.
Answer:
In situ encapsulated papillary arising in or with invasive carcinoma, NST (a single tumor) is a single invasive histology. Use rule H14 and code the histology per Table 3.
A note as been added to the 2023 breast rule H8 instructing when there is a single tumor with histology of in situ encapsulated papillary with invasive carcinoma or solid papillary carcinoma with invasove, continue through the rules. See H14 and code the appropriate histology per Table 3.
Histologic types are becoming more complex and often have both in situ and invasive components but have a single code to identify them.
