C79.89 (Secondary malignant neoplasm of other specified sites) compared with D35.2 (Benign neoplasm of pituitary gland), from the official CMS tabular data. C79.89 and D35.2 name the same anatomical site (craniobuccal pouch) with a different neoplasm behavior. MedCoder-derived
Same anatomical site, different neoplasm behavior.
Same site — benign neoplasm (craniobuccal pouch)
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. C79.89 and D35.2 name the same anatomical site (craniobuccal pouch) with a different neoplasm behavior.
From the CMS/CDC 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.
| C79.89Secondary malignant neoplasm of other specified sites | D35.2Benign neoplasm of pituitary gland | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms | C00-D49 — Neoplasms |
| Definition | Secondary malignant neoplasm of other specified sites is a billable ICD-10-CM diagnosis code (C79.89). | Benign neoplasm of pituitary gland is a billable ICD-10-CM diagnosis code (D35.2). |
| Use additional code | — | code to identify any functional activity |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources