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SEER Inquiry System - Report
Produced: 01/02/2026 11:49 AM
Question 20220036
Inquiry Details
References:
#1: Solid Tumor Rules. Head and Neck, September 2021 Update
#2: WHO Class H & N Tumors. 5th edition, online
Question:
Solid Tumors Rules/Histology--Head and Neck: How is histology coded for head and neck primaries when a tumor is diagnosed as an invasive squamous cell carcinoma with multiple subtypes? See Discussion.
Discussion:
Example Case 1: 2022 mobile tongue tumor biopsy shows squamous cell carcinoma, basaloid non-keratinizing type.
Example Case 2: 2022 base of tongue mass biopsy shows squamous cell carcinoma, basaloid non-keratinizing type, p16 positive.
Table 5, Note 2 (Head and Neck Equivalent Terms and Definitions) instructs us to code non-keratinizing squamous cell carcinoma which is p16 positive to 8085 (Squamous cell carcinoma HPV-positive), ignoring the non-keratinizing subtype. Does p16 or HPV positivity also take priority over multiple subtypes (basaloid non-keratinizing type)?
Answer:
Assign 8083/3, basaloid squamous cell carcinoma (BSCC), in both examples. It is more important to capture the variant than to code 8085 or 8086.
WHO Classification of Head and Neck Tumors, 5th ed., states that BSCC is a distinctive form of SCC, characterized by prominent basaloid morphology, squamous differentiation, and aggressive behavior. Some primary sites capture p16 status as a Site Specific Data Item; you may record the p16 results when that is the case.
