C79.49 (Secondary malignant neoplasm of other parts of nervous system) compared with D33.4 (Benign neoplasm of spinal cord), from the official CMS tabular data. C79.49 and D33.4 name the same anatomical site (cauda equina) with a different neoplasm behavior. MedCoder-derived
Same anatomical site, different neoplasm behavior.
Same site — benign neoplasm (cauda equina)
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. C79.49 and D33.4 name the same anatomical site (cauda equina) 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.
| C79.49Secondary malignant neoplasm of other parts of nervous system | D33.4Benign neoplasm of spinal cord | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms | C00-D49 — Neoplasms |
| Definition | Secondary malignant neoplasm of other parts of nervous system is a billable ICD-10-CM diagnosis code (C79.49). | Benign neoplasm of spinal cord is a billable ICD-10-CM diagnosis code (D33.4). |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources