C13.9 (Malignant neoplasm of hypopharynx, unspecified) compared with C79.89 (Secondary malignant neoplasm of other specified sites), from the official CMS tabular data. C13.9 and C79.89 name the same anatomical site (hypopharynx) with a different neoplasm behavior.
Same anatomical site, different neoplasm behavior.
Same site — secondary malignancy (hypopharynx)
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. C13.9 and C79.89 name the same anatomical site (hypopharynx) 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.
| C13.9Malignant neoplasm of hypopharynx, unspecified | C79.89Secondary malignant neoplasm of other specified sites | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Malignant neoplasm of hypopharynx, unspecified is a billable ICD-10-CM diagnosis code (C13.9). | Secondary malignant neoplasm of other specified sites is a billable ICD-10-CM diagnosis code (C79.89). |
| Includes | Malignant neoplasm of hypopharyngeal wall NOS | — |
| Use additional code | code to identify: exposure to environmental tobacco smoke (Z77.22) exposure to tobacco smoke in the perinatal period (P96.81) | — |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources