Primary malignant fibrous histiocytoma of the liver: imaging features of five surgically confirmed cases

Background: The purpose of the present study was to describe the various imaging features of primary malignant fibrous histiocytoma (MFH) of the liver, a rare tumor of mesenchymal origin. Methods: Sonography (n= 5), computed tomography (CT; n= 5), magnetic resonance (MR) imaging (n= 2), and hepatic arteriography (n= 3) in five patients who underwent partial hepatectomy for tumor resection were retrospectively reviewed and correlated with pathologic findings. Results: All tumors were clearly demarcated from surrounding hepatic parenchyma in sectional imaging with (n= 2) or without (n= 3) a fibrous capsule, which was pathologically verified. Internal architecture of abundant fibrosis, myxoid degeneration, and/or hemorrhagic necrosis reflected the sonographic, CT and MR imaging findings. Marginal tumor staining without definite tumor vasculature was the main feature of hepatic arteriography. There was no intratumoral calcification. All three tumors involving the right lobe of the liver invaded the right hemidiaphragm. Conclusion: Although there were no unique findings of primary hepatic MFH, a combined interpretation of various imaging modalities may elucidate the malignant nature of the tumor. Received: 20 May 1998/Accepted after revision: 1 July 1998