Hepatic metastases of soft tissue angiosarcoma: CT and MR imaging findings

Background: We describe the computed tomographic (CT) and magnetic resonance imaging (MRI) findings of hepatic metastases caused by soft tissue angiosarcomas to clarify the relation between radiologic appearances and clinicopathologic features. Methods: CT and MR examinations of 13 patients with hepatic metastases of soft tissue angiosarcoma, were retrospectively analyzed. Results: Contrast-enhanced CT images showed multiple hypoattenuating lesions relative to the adjacent liver parenchyma. Lesions contained peripheral areas of enhancement in eight patients (62%). Tumors showed cystic attenuation with fluid-fluid levels, which were suggestive of hemorrhage in five patients (38%). In one patient (8%) with cystic attenuation and fluid-fluid levels, lesions also contained marked enhanced nodular portions located centrally or peripherally. On T1-weighted MR images, all four liver tumors appeared heterogeneous and hypointense relative to adjacent liver parenchyma. Fluid-fluid levels were identified on T2-weighted MR images in five patients (38%). After an intravenous bolus of gadolinium-based contrast material was administered, slight peripheral enhancement was seen in three patients (75%). Conclusion: The common CT findings of metastatic angiosarcoma in our series were multiple hypoattenuating lesions often associated with nodular enhancement and cystic lesions with hemorrhagic change.