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SEER Inquiry System - Report
Produced: 07/05/2025 6:28 PM
Question 20180078
Inquiry Details
References:
Solid Tumor Rules. Breast
Question:
Solid Tumor Rules (2018)/Histology--Breast: How is histology coded and which rule applies for a single in situ tumor that is described as an encapsulated papillary carcinoma (EPC) with conventional ductal carcinoma in situ (DCIS)? See Discussion.
Discussion:
Patient had a breast excision that proved a single tumor with no evidence of invasive carcinoma. The final diagnosis stated: Size (extent) of EPC DCIS: Spanning approximately 1.3 cm. The pathologist did not describe separate foci of DCIS; only one tumor comprised of both encapsulated papillary carcinoma and DCIS. The encapsulated papillary carcinoma was not described as invasive. The pathology noted: This case is best classified as EPC conventional DCIS. No conventional stromal invasion is identified. Solid Tumor Rule M2 confirms a single tumor is a single primary.
However, there does not appear to be an H Rule that instructs how to code histology. The Single Tumor: In Situ Only module, has only three H Rules and none of them apply to this case. The patient does not have Paget disease (H1), does not have a single histology (H2, there are multiple histologies present as DCIS and EPC are listed on different rows in Table 3) and does not have DCIS and LCIS (H3). How does one arrive at the correct histology for this case?
Answer:
Code histology to 8500/2. Per April 2019 update: Rule H5 applies: Code DCIS 8500/2 when there is a combination of DCIS and any other carcinoma in situ.
The 4th Ed WHO Tumors of the Breast states that tumors with encapsulated papillary carcinoma in situ in the absence of DCIS in the surrounding tissue have a very favorable prognosis. Only tumors without DCIS should be coded to 8504/2. The component of DCIS will determine treatment.
