C78.4 (Secondary malignant neoplasm of small intestine) compared with D13.2 (Benign neoplasm of duodenum), from the official CMS tabular data. C78.4 and D13.2 name the same anatomical site (duodenum) with a different neoplasm behavior. MedCoder-derived
Same anatomical site, different neoplasm behavior.
Same site — benign neoplasm (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. C78.4 and D13.2 name the same anatomical site (duodenum) 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.
| C78.4Secondary malignant neoplasm of small intestine | D13.2Benign neoplasm of duodenum | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms | C00-D49 — Neoplasms |
| Definition | Secondary malignant neoplasm of small intestine is a billable ICD-10-CM diagnosis code (C78.4). | Benign neoplasm of duodenum is a billable ICD-10-CM diagnosis code (D13.2). |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources