C48.2
BillableMalignant neoplasm of peritoneum, unspecified
HCC Category Mapping
V28HCC 20 — Lung and Other Severe Cancers
0.000V24HCC 9 — Lung and Other Severe Cancers
0.973ESRDHCC 9 — Lung and Other Severe Cancers
0.000RxHCCHCC 22 — Cancer, Other Specified Sites
0.000What This Code Means
A malignant (cancerous) tumor that develops in the peritoneum, which is the thin membrane lining the abdominal cavity, when the specific location within the peritoneum is not specified.
Coding Tips
- •Use this code only when the peritoneal cancer site is unspecified; if a specific location is documented, use a more specific C48 code
- •This code is often used for peritoneal mesothelioma or primary peritoneal cancer when exact anatomical location is unclear
Clinical Significance
Malignant neoplasm of peritoneum, unspecified is a non-specific code that should trigger a query for more detailed anatomical information. While it carries the same high HCC weight as other C48 codes, unspecified codes carry elevated audit risk and should be used only when specific peritoneal sites cannot be determined.
Documentation Requirements
- ✓Pathology confirming primary peritoneal malignancy
- ✓Documentation explaining why specific peritoneal site is unknown
- ✓Evidence of provider query attempt for site specification
- ✓Imaging showing peritoneal involvement
- ✓Distinction from secondary/metastatic peritoneal disease
Commonly Confused Codes
C48.1 (Specified parts of peritoneum) — preferred when any specific peritoneal site is documentedC48.0 (Retroperitoneum) — anatomically distinct from peritoneumC78.6 (Secondary malignant neoplasm of peritoneum) — metastatic disease, not primaryC45.1 (Mesothelioma of peritoneum) — specific histological type that has its own code
Code Hierarchy
└C48Malignant neoplasm of retroperitoneum and peritoneum└C48.2Malignant neoplasm of peritoneum, unspecified
└C48.2Malignant neoplasm of peritoneum, unspecified