Hemangiopericytoma of the greater omentum: US and CT appearance.

The US, Doppler and CT appearances in a patient with hemangiopericytoma of the greater omentum are presented. Ultrasound revealed a solid mass with heterogeneous echo pattern, well-defined margins and marked vascularity with low impedance flow (mean resistive index 0.42). The tumour was mobile. It was detected below the left kidney at the first US examination and had migrated into the pelvis 14 days later. At CT the tumour demonstrated strong but brief peripheral enhancement and a central hypodense scar.