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SEER Inquiry System - Report
Produced: 06/02/2023 5:31 PM
Question 20220018
Inquiry Details
References:
#1: Solid Tumor Rules. 2 September 2021 Update
#2: WHO Class Endocrine Tumors, 78; 81-91. 4th edition
Question:
Solid Tumor Rules/Histology--Thyroid: What is the correct histology code for the following thyroid primary with multiple tumors abstracted as one primary diagnosed prior to 2021? See Discussion.
Discussion:
2016 Total thyroidectomy, Multifocal
-Dominant Tumor: Right Lobe, Papillary thyroid carcinoma (8260/3)
-Tumors two through five: Three tumors Papillary thyroid carcinoma (8260/3), and one tumor Papillary thyroid carcinoma, follicular variant (8340/3)
-An additional tumor: Non-invasive follicular thyroid neoplasm with papillary-like nuclear features (8343/2)
Answer:
Code this multifocal thyroid carcinoma, single primary, as papillary thyroid carcinoma, follicular variant (8340/3) using Solid Tumor Rules, Other Sites, Rule H13 that says to code the most specific histologic term. We consulted with our endocrine specialty pathologist and when there is a mix of papillary and follicular variants, assign 8340.
Non-invasive follicular thyroid neoplasm with papillary-like nuclear features is coded as 8349/1 beginning in 2021. According to the WHO Classification of Endocrine Organs, 4th edition, it was formerly classified as non-invasive encapsulated follicular variant of PTC (FVPTC) (8343/2) but was reclassified based on extremely low malignant potential.
