C71.0 (Malignant neoplasm of cerebrum, except lobes and ventricles) compared with C79.31 (Secondary malignant neoplasm of brain), from the official CMS tabular data. C71.0 and C79.31 name the same anatomical site (basal ganglia) with a different neoplasm behavior.
Same anatomical site, different neoplasm behavior.
Same site — secondary malignancy (basal ganglia)
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. C71.0 and C79.31 name the same anatomical site (basal ganglia) 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.
| C71.0Malignant neoplasm of cerebrum, except lobes and ventricles | C79.31Secondary malignant neoplasm of brain | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms | C00-D49 — Neoplasms |
| Definition | Malignant neoplasm of cerebrum, except lobes and ventricles is a billable ICD-10-CM diagnosis code (C71.0). | Secondary malignant neoplasm of brain is a billable ICD-10-CM diagnosis code (C79.31). |
| Includes | Malignant neoplasm of supratentorial NOS | — |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources