An official website of the United States government
Home
SEER Inquiry System - Report
Produced: 05/21/2025 3:37 AM
Question 20170065
Inquiry Details
References:
2007 MP/H Rules. Other Sites
Question:
MP/H Rules/Histology--Thyroid: How should histology be coded for a single tumor with final diagnosis undifferentiated (anaplastic) carcinoma arising in association with papillary thyroid carcinoma and the Summary Cancer Data states Histologic type: Undifferentiated (anaplastic) carcinoma only? See Discussion.
Discussion:
The Summary Cancer Data does not seem to describe a more specific histology, but it does describe the tumor histology with the worst outcome and the most extensive tumor. The anaplastic carcinoma grossly extended into skeletal muscle and gave rise to multiple regional lymph node metastases. The more appropriate histology seems to be 8021.
However, current MP/H Rules for a single tumor indicate the histology should be coded to the numerically higher histology code (8260). Coding the histology to 8260 does not account for the more aggressive tumor. Should this histology be 8260 or 8021?
Answer:
Code the most specific histologic term, 8260, for papillary carcinoma of the thyroid using Multiple Primary/Histology Rule H13 for Other Sites (single tumor, invasive section). Use text fields to describe the complete histology.
