Primary hepatic angiosarcoma: findings at CT and MR imaging

PURPOSE: To evaluate and describe cross-sectional imaging findings in patients with pathologically confirmed primary hepatic angiosarcoma. MATERIALS AND METHODS: Findings from imaging examinations in 13 patients with pathologically confirmed primary hepatic angiosarcoma were retrospectively reviewed (computed tomographic [CT] images obtained in 10 patients and magnetic resonance [MR] images obtained in five patients were available for review). Two gastrointestinal radiologists evaluated lesion number, size, attenuation and signal intensity characteristics, and the pattern and degree of contrast material enhancement. Medical records were reviewed for clinical features associated with angiosarcoma. RESULTS: Angiosarcoma appeared as multiple nodules (n = 6), as dominant masses (n = 6), or as a diffusely infiltrating lesion (n = 1). Multiple nodules were hypoattenuating at unenhanced and contrast material--enhanced CT (six of six patients). When dominant masses were encountered at MR imaging, T2-weighted MR imaging demonstrated heterogeneous internal architecture (four of four patients) similar to that of hepatocellular carcinoma. Multiphase contrast-enhanced CT and MR images showed dominant masses to have heterogeneous and progressive enhancement (three of three patients). Clinical features associated with angiosarcoma included splenic metastases (six of 13 patients), thrombocytopenia (seven of 13 patients), disseminated intravascular coagulation (four of 13 patients), and hemolytic anemia (three of 13 patients). CONCLUSION: Primary hepatic angiosarcoma exhibits a spectrum of appearances that reflect its varied pathologic features.