Pitfalls in the diagnosis of retroperitoneal adenopathy.

From an experience of approximately 4 000 body computed tomographic scans we identified 14 patients in whom non-nodal structures mimicked the appearance of retroperitoneal adenopathy; six of the patients are discussed in detail. Causes of a wrong diagnosis include varices, normal veins, aneurysms, localized hemorrhage, extramedullary hematopoiesis, and bowel adhesions. More common causes such as non-opacified bowel are not included. We emphasize ways to avoid these infrequent, though often clinically important, diagnostic pitfalls.