Ultrasonographic diagnosis of primary hepatic undifferentiated pleomorphic sarcoma

Objective To explore the ultrasonographic features of primary hepatic undifferentiated pleomorphic sarcoma (UPS) to increase the rate of accurate clinical diagnosis. Methods We analyzed all (n = 7) primary hepatic UPS cases who attended Our Hospital from 2010 to 2021 in terms of morphology, size, echogenicity, borders, blood flow signal, posterior echoes, and other ultrasonographic features. Results All studied masses were solitary and mainly invaded one lobe of the liver. All the masses had diameters exceeding 5.0 cm and were nonencapsulated. They mostly had clear borders and regular morphologies (6 of 7 [85.7%]). Echogenicity was hypoechoic (2 of 7 [28.6%]) or heterogeneous (5 of 7 [71.4%]). Echogenicity was enhanced at the posterior aspect in all cases. None of the cases exhibited calcification, but some showed mass liquefaction (2 of 7 [28.6%]). Blood flow signal from the mass was rich (2 of 7 [28.6%]), mild (2 of 7 [28.6%]) or minimal (3 of 7 [42.9%]). One case in this study underwent CEUS. The margins and the internal septa, and mural or septal nodules of the mass showed mild hyperenhancement in the arterial phase and portal venous phase, but mild hypoenhancement in late phase. There were large nonenhancing areas in all three phases. Conclusion When ultrasonography reveals a solitary, relatively large, regular, and nonencapsulated mass, primary hepatic UPS should be a differential diagnosis. Combining clinical findings with imaging modalities can increase the likelihood of an accurate diagnosis.