C70.1 (Malignant neoplasm of spinal meninges) compared with C79.49 (Secondary malignant neoplasm of other parts of nervous system), from the official CMS tabular data. C70.1 and C79.49 name the same anatomical site (arachnoid) with a different neoplasm behavior.
Same anatomical site, different neoplasm behavior.
Same site — secondary malignancy (arachnoid)
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. C70.1 and C79.49 name the same anatomical site (arachnoid) 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.
| C70.1Malignant neoplasm of spinal meninges | C79.49Secondary malignant neoplasm of other parts of nervous system | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms | C00-D49 — Neoplasms |
| Definition | Malignant neoplasm of spinal meninges is a billable ICD-10-CM diagnosis code (C70.1). | Secondary malignant neoplasm of other parts of nervous system is a billable ICD-10-CM diagnosis code (C79.49). |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources