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SEER Inquiry System - Report
Produced: 08/27/2025 7:44 AM
Question 20190031
Inquiry Details
References:
SSDI Manual, 40. Schema Discriminator 1
Question:
Primary site--Head & Neck: Are cases with positive cervical lymph nodes that are EBV positive (EBV+) coded to the nasopharynx, and cases with positive cervical lymph nodes that are p16 positive (p16+) coded to the oropharynx, when no primary site is identified? See Discussion.
Discussion:
This question involves positive cervical lymph nodes with an unknown primary site. The SEER Manual says under the coding instructions for Primary Site:
14. b.Use the NOS category for the organ system or the Ill-Defined Sites (C760-C768) if the physician advisor cannot identify a primary site.
Note: Assign C760 for Occult Head and Neck primaries with positive cervical lymph nodes.
Schema Discriminator 1: Occult Head and Neck Lymph Nodes is used to discriminate between these cases and other uses of C760. Does SEER agree with AJCC that cases with positive cervical lymph nodes that are EBV+ should be coded to the nasopharynx and cases with positive cervical lymph nodes that are p16+ should be coded to the oropharynx, if no primary site is identified?
Answer:
Assign primary site C119 (nasopharynx) for occult head and neck tumors with cervical metastasis in Levels I-VII, and other group lymph nodes that are positive for Epstein "Barr virus (EBV+) (regardless of p16 status) encoded small RNAs (EBER) identified by in situ hybridization.
Assign primary site C109 (oropharynx) for occult head and neck tumors with cervical metastasis in Levels I-VII, and other group lymph nodes, p16 positive with histology consistent with HPV-mediated oropharyngeal carcinoma (OPC).
