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

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