SITE SPECIFIC DATA ITEMS (SSDI)/ GRADE

Description

In AJCC 8th edition, a new chapter was introduced for situations when there are positive cervical nodes (head and neck nodes for Levels I-VII, and other group), however, the primary tumor is not evident (occult tumor), and the primary tumor is suspected to be from the head and neck region (primary sites C00-C14, C30-32). * If the differential diagnosis includes non-head and neck sites, the primary site should be coded to C809 * ***Example***: path report states metastasis to the cervical lymph node could be from a head and neck primary, lung primary, or gynecologic primary * If there is no indication that the cervical lymph node is from a head and neck site, then the primary site should be coded to C809 * If the tumor is found to be EBV+ or p16+. See Coding Guidelines below. * If the tumor is suspected to be from a head and neck site, or a potential head and neck site is indicated by the physician, see Coding Guidelines below. To develop a software algorithm that can be used to send the registrar to the right chapter/schema, this schema discriminator was developed. To get to this schema discriminator, the registrar will code C760 (head and neck, NOS) when there is a suspected head and neck tumor, yet the primary site is not known, and/or the primary tumor was not identified. The schema discriminator will then be brought up. * Note: If the physician “suspects” or “assigns” a specific head and neck subsite, the registrar is still to assign C760 so that the correct staging information can be abstracted. * ***Example***: FNA of cervical lymph node metastases shows squamous cell carcinoma, p16 negative. Workup shows no evidence of primary tumor, although physician states this may be a laryngeal primary based on “best guess”. * Even though the primary site is suspected to be larynx, primary site would still be coded to C760. For all head and neck sites, except for oropharynx p16+ and nasopharynx EBV positive, no evidence of primary tumor (T0) does not exist in the individual AJCC chapters or EOD schemas. These cases are collected as unknown head and neck primary (C760), which will have no evidence of primary tumor. This Schema ID was designed specifically to group together these cases of an occult primary, a tumor that is not identified on physical exam or imaging techniques.

Notes

**Note:** **Schema Discriminator for C760** * This schema discriminator is used to discriminate between head and neck tumors with unknown primary site coded as C760. * **00060: Cervical Lymph Nodes and Unknown Primary** Occult head and neck tumor with cervical metastasis in Levels I-VII, and other group lymph nodes without a p16 immunostaining or with negative results and without an Epstein-Barr virus (EBV) encoded small RNAs (EBER) by in situ hybridization performed or with negative results are staged using the AJCC Cervical Lymph Nodes and Unknown Primary Tumors of the Head and Neck Staging System. **Assign primary site C760; code the schema discriminator accordingly.** * **00090: Nasopharynx** Occult head and neck tumors with cervical metastasis in Levels I-VII, and other group lymph nodes that is positive for Epstein-Barr virus (EBV+) (regardless of p16 status) encoded small RNAs (EBER) identified by in situ hybridization are staged using the AJCC Nasopharynx Staging System. **Assign primary site C119; do NOT code this discriminator. ** * **00100: HPV-Mediated (p16+) Oropharyngeal Cancer** 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), are staged using the AJCC HPV-Mediated (p16+) Oropharyngeal Cancer Staging System. **Assign primary site C109; do NOT code this discriminator** * **99999: Ill-Defined Other** If the tumor is not occult or does not have cervical metastasis in Levels I-VII, and other group lymph nodes, it is not included in the AJCC Cervical Lymph Nodes and Unknown Primary Tumors of the Head and Neck Staging System and will be classified as Ill-Defined Other for Summary Staging