Malignant cardiac fibrous histiocytomas and angiosarcomas: MR features.

Primary tumors of the heart are rare, and one-third of them are malignant. The magnetic resonance (MR) features, their specificity, and significance in two patients with malignant fibrous histiocytoma and three patients with angiosarcoma are presented and the literature briefly reviewed. Malignant fibrous histiocytoma occurred in the left atrium and demonstrated slightly heterogeneous intermediate signal intensity on T1-weighted images and high signal intensity on T2-weighted images. The angiosarcomas involving primarily the right heart were more varied in MR appearance with heterogeneous signals. The extensive angiosarcomas almost circumferentially involving the epicardium and pericardium showed the "cauliflower" appearance with focal areas of increased signal intensity probably related to thrombosis or hemorrhage. Magnetic resonance provided detailed anatomic information and characterization of malignant cardiac tumors.