Ring-enhancing lesions on computed tomography.

In our case, the history, clinical findings, negative biochemistry and CT and MIBG scans indicated that the lesion might be a non-catecholamine-secreting paraganglioma. The final diagnosis of a vascular malformation was unexpected but revealed an interesting differential diagnosis of a rare pathology. Retroperitoneal vascular malformations of the choledochus, kidney and pancreas have been described but are rare conditions which may cause digestive or urinary tract bleeding.8 In this case the symptoms were unrelated to the excised lesion.