FDG PET/CT in a Case of Primary Angiosarcoma of the Kidney.

Primary angiosarcoma of the kidney is a rare aggressive malignancy. We describe MRI and FDG PET/CT findings in a case of primary renal angiosarcoma with hepatic, pulmonary, and bony metastases. The large primary tumor showed extensive necrosis and increased FDG uptake in the nonnecrotic components. Multiple metastatic lesions in the liver, lung, and bones were detected by FDG PET/CT. Most of the hepatic metastases seen on MRI were missed on FDG PET/CT due to low FDG avidity.