C17.0 (Malignant neoplasm of duodenum) compared with D37.2 (Neoplasm of uncertain behavior of small intestine), from the official CMS tabular data. C17.0 and D37.2 name the same anatomical site (duodenum) with a different neoplasm behavior.
Same anatomical site, different neoplasm behavior.
Same site — uncertain behavior (duodenum)
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. C17.0 and D37.2 name the same anatomical site (duodenum) 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.
| C17.0Malignant neoplasm of duodenum | D37.2Neoplasm of uncertain behavior of small intestine | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Malignant neoplasm of duodenum is a billable ICD-10-CM diagnosis code (C17.0). | Neoplasm of uncertain behavior of small intestine is a billable ICD-10-CM diagnosis code (D37.2). |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources