#2: Head & Neck
Source 1: ICD-O-3 SEER Site/Histology Validation List
Notes: June 18, 2019
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.
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.
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.