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SEER Inquiry System - Report
Produced: 06/21/2026 1:45 PM
Question 20200017
Inquiry Details
References:
ICD-O-3 SEER Site/Histology Validation List. June 18, 2019
Question:
Histology--Head & Neck: Why is 8070 not listed as a valid histology for ill-defined sites as squamous cell carcinoma arises in the head and neck sites. See Discussion.
Discussion:
Per the site validation list: https://seer.cancer.gov/icd-o-3/sitetype.icdo3.20190618.pdf#search=site%20validation, ill-defined sites (ILL-DEFINED C760-C768) does not include 8070- Squamous cell carcinoma as a valid histology. Therefore when a Cervical Lymph Node and Unknown Primary Tumor of the Head and Neck is submitted with a C760 and 8070/3, it requires an override be set.
Answer:
Histology code 8070 has been added to C760 on the site validation list. It will be updated for 2021. Continue to override this combination for now.
