C10.0 (Malignant neoplasm of vallecula) compared with C79.89 (Secondary malignant neoplasm of other specified sites), from the official CMS tabular data. C10.0 and C79.89 name the same anatomical site (oropharynx) with a different neoplasm behavior.
Same anatomical site, different neoplasm behavior.
Same site — secondary malignancy (oropharynx)
The behavior documented for the site — malignant primary, secondary, carcinoma in situ, benign, uncertain or unspecified — decides which column of the neoplasm table, and therefore which code, applies.
Source: CMS Table of Neoplasms
Same site, different neoplasm behavior. C10.0 and C79.89 name the same anatomical site (oropharynx) with a different neoplasm behavior.
From the CMS Table of Neoplasms: the behavior documented for that site — malignant primary, secondary, carcinoma in situ, benign, uncertain or unspecified — decides which column, and therefore which code, applies.
| C10.0Malignant neoplasm of vallecula | C79.89Secondary malignant neoplasm of other specified sites | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms | C00-D49 — Neoplasms |
| Definition | Malignant neoplasm of vallecula is a billable ICD-10-CM diagnosis code (C10.0). | Secondary malignant neoplasm of other specified sites is a billable ICD-10-CM diagnosis code (C79.89). |
| Use additional code | code to identify: alcohol abuse and dependence (F10.-) exposure to environmental tobacco smoke (Z77.22) | — |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources