D33.4 (Benign neoplasm of spinal cord) compared with D43.4 (Neoplasm of uncertain behavior of spinal cord), from the official CMS tabular data. D33.4 and D43.4 name the same anatomical site (cauda equina) with a different neoplasm behavior.
Same anatomical site, different neoplasm behavior.
Same site — uncertain behavior (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. D33.4 and D43.4 name the same anatomical site (cauda equina) 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.
| D33.4Benign neoplasm of spinal cord | D43.4Neoplasm of uncertain behavior of spinal cord | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Benign neoplasm of spinal cord is a billable ICD-10-CM diagnosis code (D33.4). | Neoplasm of uncertain behavior of spinal cord is a billable ICD-10-CM diagnosis code (D43.4). |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources