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SEER Inquiry System - Report
Produced: 12/22/2025 3:18 PM
Question 20220017
Inquiry Details
References:
#1: WHO Class Endocrine Tumors, 86. 4th edition
#2: 2021 ICD-O-3.2 Update
Question:
Histology--Thyroid: What is the correct histology code for a thyroid resection showing papillary carcinoma, tall cell variant with oncocytic features with 30% of largest tumor (right) is tall cell variant and both foci contain benign multinucleated giant cells? See Discussion.
Discussion:
There is an ICD-O histology code for papillary carcinoma, tall cell (8344/3) as well as papillary carcinoma, oxyphilic cell (8342/3). Per SINQ 20150045, the term oncocytic is synonymous with oxyphilic in this context.
The term “variant” can be used for the Other Sites (non-updated STR sites) primaries when the ICD-O-3.2 (or ICD-O-3 for older cases) includes the term “variant” in the histology name. The MPH General Instructions did not include the term “variant” as a term that can be used to code histology.
Answer:
Code papillary carcinoma, tall cell variant with oncocytic features to papillary carcinoma, tall cell (C73.9) (8344/3). The WHO Classification of Endocrine Organs states that this variant is composed of cells that are as tall as they are wide, and show abundant eosinophilic (oncocytic-like) cytoplasm. Tall cells must account for greater than or equal to 30% of all tumor cells.
