Peritoneal Sarcomatosis

Axial CT image of the abdomen shows soft-tissue implants and omental caking (arrows) with small ascites.

Peritoneal Surface Malignancy
- Carcinomatosis
- Lymphomatosis
- Sarcomatosis
- Mesothelioma
- Desmoplastic small round cell tumor

Peritoneal Sarcomatosis
- Disseminated intraperitoneal spread of sarcoma in the absence of significant extraabdominal sites of disease
- Rare disease.
- Most commonly due to GI stromal tumor (GIST), liposarcoma and leiomyosarcoma

Imaging Findings
- Similar to other peritoneal surface malignancy: soft-tissue implants along peritoneum and omentum
- Often hypervascular, and with variable amount of ascites (differ from other peritoneal surface tumors)

Our case: Sarcomatosis due to GIST. Ascites is believed to be due to treatment with imatinib


Reference:
Oei TN, Jagannathan JP, Ramaiya N, Ros PR. Peritoneal sarcomatosis versus peritoneal carcinomatosis: imaging findings at MDCT. AJR 2010; 195:W229-W235.