Amyloidosis: diffuse involvement of the retroperitoneum.

Systemic amyloidosis diffusely involving the retroperitoneum has not, to the authors' knowledge, been previously reported. The computed tomographic scans of a 68-year-old man showed evidence of diffuse, nonenhancing thickening of the entire retroperitoneum. This appearance mimicked retroperitoneal fibrosis, but the diagnosis of amyloidosis was confirmed at autopsy.