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SEER Inquiry System - Report
Produced: 03/28/2026 1:06 PM
Question 20100015
Inquiry Details
References:
2007 SEER Manual, 90-91, 93-94
Question:
Type of Multiple Tumors/Multiplicity Counter--Breast. Are the data items "Type of Multiple Tumors Reported as One Primary" and "Multiplicity Counter" related? How should they be coded for breast cases in which there are multiple measured invasive tumors, plus DCIS which is not measured nor stated whether it is separate from the invasive tumors? See Discussion.
Discussion:
For example, path report states only "multifocal invasive ductal carcinoma, 1.5 cm and 0.8 cm, and low-grade DCIS." The Multiplicity Counter instructions tell us to ignore/do not count foci that are not measured. Should we interpret this to mean, count only the two invasive foci and ignore the DCIS? Should Type of Multiple Tumors then be coded 30 or 40, because only the invasive tumors are coded in Multiplicity Counter?
Answer:
Code Type of Multiple Tumors 30 [in situ and invasive]. The code in Type of Multiple Tumors may or may not reflect the tumors that were counted in Multiplicity Counter. For this case, it is correct to code 02 in multiplicity counter.
Cancer Site Category:
Breast
Data Item Category:
N/A
Other Category:
N/A
Year:
2010
