Primary retroperitoneal angiosarcoma: MR imaging features.

We report a rare case of retroperitoneal angiosarcoma in a 72-year-old man who presented with abdominal pain. Diagnosis was obtained histologically after radical excision of the tumour. Fat-suppression MRI after intravenous administration of the contrast agent gadolinium-DTPA was able to define tissue planes between the lesion and the adjacent structures, suggesting the vascular nature of the lesion, and provided useful information for an accurate surgical approach. To the best of our knowledge, this is the first report that illustrates the MRI characteristics of a retroperitoneal angiosarcoma.