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SEER Inquiry System - Report
Produced: 06/04/2026 11:03 AM
Question 20250019
Inquiry Details
References:
#1: 2025 SEER Manual, 132-136. Tumor Size Summary
#2: ACR BI-RADS, Breast-MRI-Reporting.pdf. Atlas - Breast MRI
Question:
SEER Manual/Tumor Size Summary--Breast: Can the size of a non-mass enhancement (NME) be used if it represents the largest size within the appropriate time frame to code tumor size summary when neoadjuvant therapy is administered? Clinical and pathologic tumor sizes are no longer collected for 2024 and 2025 cases. See Discussion.
Discussion:
In the SEER Program Coding and Staging Manual 2023, under clinical tumor size (page 115, item #12), it states: “For breast tumors, clinical size may be recorded based on the size of a non-mass enhancement (NME). NME is defined as an enhancing abnormality that is not associated with the three-dimensional volume of a mass, shape, and outlining, and it is separate from Background Parenchymal Enhancement (BPE).” This guidance does not appear to have been carried forward into the Tumor Size Summary coding instructions.
Answer:
Do not use the NME size from magnetic resonance imaging (MRI) to code tumor size when both tumor size and NME size are stated or if NME is the only size available. The size of the solid tumor mass takes priority over the size of the NME when provided separately and the NME is larger.
The American College of Radiology, Breast Imaging Reporting and Data System (BI-RADS) defines NME as an area of enhancement on MRI that does not belong to a 3D mass or have distinct features of a mass. It is a separate descriptor from size that includes modifiers describing enhancement patterns with a specific MRI pattern.
