ICD-10 Code C48.2 – Malignant neoplasm of peritoneum, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C48.2 – Malignant neoplasm of peritoneum, unspecified
What it is
C48.2 identifies a malignant tumor arising in the peritoneum when the record does not specify a more exact site. Use it for primary peritoneal cancer or peritoneal malignancy documented without further detail.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include abdominal distension, pain, ascites, or nonspecific gastrointestinal symptoms, but the diagnosis should be supported by imaging, pathology, or specialist assessment.
When to use this code
Use C48.2 when the provider documents malignancy of the peritoneum and no subsite is stated. It also fits cases where the chart says peritoneal cancer, peritoneal carcinoma, or primary peritoneal malignancy without more specific anatomic detail. If the record names another primary site with peritoneal spread, code the documented primary and metastatic disease instead.
Do not use for
Do not use this code for benign peritoneal conditions, inflammatory disease, or malignant disease clearly documented as arising elsewhere. Check documentation if the note describes peritoneal metastasis from another primary tumor.
Coding tip
Assign C48.2 only when the peritoneum is the documented malignant site and no more specific peritoneal location is available.