Malignant neoplasm of retroperitoneum and peritoneum (C48) ICD-10-CM
The C48 code range covers malignant neoplasm of retroperitoneum and peritoneum with 5 ICD-10-CM diagnosis codes. 4 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Codes in the C48 Range 5 codes · 4 billable
- C48 Malignant neoplasm of retroperitoneum and peritoneumNon-billable
- C48.0 Malignant neoplasm of retroperitoneum
- C48.1 Malignant neoplasm of specified parts of peritoneum
- C48.2 Malignant neoplasm of peritoneum, unspecified
- C48.8 Malignant neoplasm of overlapping sites of retroperitoneum and peritoneum
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the C48 range.
Mesocolon
The fold of peritoneum by which the COLON is attached to the posterior ABDOMINAL WALL.
Omentum
A double-layered fold of peritoneum that attaches the STOMACH to other organs in the ABDOMINAL CAVITY.
About the C48 Code Range
ICD-10 code C48 covers malignant tumors affecting the retroperitoneum and peritoneum, areas in the abdominal cavity. These codes are specifically used to classify cancers originating in these regions, including various specialized forms of retroperitoneal and peritoneal malignancies.
The section includes C48.0 for malignant neoplasms of the retroperitoneum, which encompass tumors such as retroperitoneal sarcomas, liposarcomas, and primary malignant neoplasms of nearby tissues like perirenal and periadrenal areas. The synonym list helps clarify that terms like "retroperitoneal sarcoma" or "primary giant cell sarcoma of retroperitoneum" all fall under this code. C48.1 codes malignant neoplasms of specific parts of the peritoneum, including the omentum, mesocolon, and rectouterine pouch (pouch of Douglas), covering various sarcomas and adenocarcinomas localized to these sites. For cases where the peritoneal site is unspecified, C48.2 is used; it covers terms linked to general malignant tumors of the peritoneum, such as primary adenocarcinoma or sarcoma. Lastly, C48.8 identifies malignant neoplasms overlapping both retroperitoneal and peritoneal sites, useful when tumors span these adjacent regions. These distinctions are crucial for correct coding of gastrointestinal cancers involving these complex anatomical sites.
Questions About This Page
How many billable codes are in the C48 range?
Of the 5 codes in this range, 4 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the C48 range classify?
The range classifies malignant neoplasm of retroperitoneum and peritoneum. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
