Primary hepatic undifferentiated pleomorphic sarcoma: CT and angiographic findings in two cases

Primary hepatic undifferentiated pleomorphic sarcoma (UPS) is an extremely rare disease entity whose imaging characteristics are not well documented in literature. We present two cases of primary hepatic UPS with contrasting disease courses, and their CT and angiographic findings in this report. Imaging characteristics include inhomogeneous appearance and peripheral enhancement pattern, with necrosis and delayed gradual fill-in enhancement more evident in the larger tumor. Although imaging findings are not specific, being familiar with the common manifestations of primary hepatic UPS will allow radiologists to include it in their differential diagnosis list for suspected sarcomatous or mesenchymal tumors of liver.