Retroperitoneal Castleman's disease: report of two cases.

Castleman's disease (angiofollicular lymph node hyperplasia) is a rare benign disorder characterized by hypervascular lymphoid hyperplasia. It usually manifests as an asymptomatic, solitary mediastinal tumor, and seldom presents as an isolated retroperitoneal mass. We report two cases of histologically proven Castleman's disease occurring in the retroperitoneum. Their computed tomographic and angiographic features are presented, and the characteristics of this condition are described. Recognition of Castleman's disease in the retroperitoneal area is helpful in avoiding massive intraoperative hemorrhage and an unnecessarily extensive operation.