Question: If you had multiple papillary tumors such as a micropapillary 8260/3 and a papillary tall cell 8344/3 would we apply rule M6 (single primary) or M17(multiple primaries)?
Answer: Rule M17 Tumors with ICD-O-3 histology codes that are different at the first (xxxx), second (xxxx) or third (xxxx) number are multiple primaries. **
Sent: Friday, July 1, 2022, 10:36 AM
M6 applies to tumors with both follicular and papillary, not multiple types of papillary carcinomas or multiple types of follicular carcinomas.
So, if there are separate tumors, first assign a histology for each. Then work through the rules. A long-standing rule in North America, is micropapillary thyroid tumors are coded as papillary carcinoma 8260/3.
For your example, assuming the tumors are separate, micropapillary thyroid carcinoma is coded 8260/3 and Tall cell coded 8344/3. The first rule that applies is M17: they are multiple primaries.
Note: Thyroid histologies are complex and often times multiple subtypes/variants are identified in resected specimens. There continues to be concern of over-reporting thyroid malignancies. Thyroid tumors seen on scans are not routinely recommended for biopsy based on radiologic criteria. These tumors are followed with scans and if they meet specific criteria, then a biopsy is recommended. The Other sites rules are being revised for 2023 and will include new H rules for coding these neoplasms.