Malignant paraganglioma draining into the main portal vein.

Abdominal paraganglioma is a relatively rare tumor, and there have been no previous reports describing its contrast-enhanced ultrasonographic findings. We report a case of a lesion of unknown origin incidentally detected by ultrasound in the right upper abdomen. The lesion was markedly hypervascular and contrast-enhanced ultrasonogram showed it to be communicating with the portal vein. This communication was then confirmed by angiogram. Such an arteriovenous communication through paraganglioma has been recently reported, and a diagnosis of a paraganglioma should be considered when contrast-enhanced ultrasonogram shows a solid mass of unknown origin draining directly into the venous system.