C48.1
BillableMalignant neoplasm of specified parts of peritoneum
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
Cancer that develops in the peritoneum, which is the lining of the abdominal cavity. This malignant tumor affects the membrane that covers abdominal organs.
Coding Tips
- •Peritoneum is the lining; retroperitoneum (C48.0) is behind the lining—verify correct site
- •Document whether primary peritoneal cancer or secondary involvement from another primary site
Clinical Significance
Malignant neoplasm of specified parts of the peritoneum includes primary peritoneal carcinoma and peritoneal mesothelioma, distinct from metastatic peritoneal disease. Primary peritoneal cancer carries a similarly severe prognosis to advanced ovarian cancer and requires aggressive multimodal treatment including cytoreductive surgery and intraperitoneal chemotherapy.
Documentation Requirements
- ✓Pathology confirming primary peritoneal malignancy (not metastatic peritoneal disease)
- ✓Specific peritoneal sites involved (parietal, visceral, mesentery, omentum)
- ✓Histological type (serous carcinoma, mesothelioma, desmoplastic small round cell tumor, etc.)
- ✓Extent of peritoneal involvement (peritoneal carcinomatosis index if available)
- ✓Distinction from ovarian cancer with peritoneal spread
Commonly Confused Codes
C48.2 (Malignant neoplasm of peritoneum, unspecified) — use C48.1 when specific peritoneal sites are documentedC48.0 (Malignant neoplasm of retroperitoneum) — retroperitoneal, behind the peritoneum, different locationC56._ (Malignant neoplasm of ovary) — primary peritoneal serous carcinoma is coded differently from ovarian cancerC78.6 (Secondary malignant neoplasm of retroperitoneum and peritoneum) — metastatic disease, not primary
Code Hierarchy
└C48Malignant neoplasm of retroperitoneum and peritoneum└C48.1Malignant neoplasm of specified parts of peritoneum
└C48.1Malignant neoplasm of specified parts of peritoneum