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SEER Inquiry System - Report
Produced: 10/15/2025 1:04 PM
Question 20021058
Inquiry Details
References:
#1: SEER Program Code Man, 3rd Ed, 11-13
#2: 2004 SEER Manual, 11
Question:
Multiple Primaries (Pre-2007)--Breast: When simultaneously diagnosed breast tumors of the same histology in the same breast are stated by the pathologist and/or clinician to be more than one primary, should these be reported as multiple primaries? See discussion.
Discussion:
For example, based on special pathology studies that showed a difference in appearance between tumors, a pathologist may state that two ductal, NOS tumors diagnosed at the same time in the same breast represent two primaries.
Answer:
For tumors diagnosed prior to 2007:
Code as a single primary. Follow the guidelines in the SEER Program Code Manual for determining multiple primaries. Simultaneous multiple lesions of the same histologic type in the same site (same breast) are a single primary for SEER, even though the pathologist may perform special studies and state that the patient has more than one primary.
For tumors diagnosed 2007 or later, refer to the MP/H rules. If there are still questions about how this type of tumor should be coded, submit a new question to SINQ and include the difficulties you are encountering in applying the MP/H rules.
