[Castleman's disease: isolated retroperitoneal mass. Report of a case]

To describe a rare case of vascular hyaline variant of Castleman's disease presenting as a solitary mass, with special reference to the radiological findings and differential diagnosis. The literature is briefly reviewed.

A 48-year-old male presented with nonspecific pain in the left flank. Routine analyses were unremarkable. Sonographic and CT studies showed a well-defined, highly vascularized, 3.3 x 3.6 x 4 cm retroperitoneal mass. The risk of hemorrhage made a preoperative biopsy impracticable and the mass was removed surgically. The pathological analysis of the surgical specimen showed a localized retroperitoneal angiofollicular lymphoid hyperplasia (vascular hyaline variant).

Castleman's disease can rarely present as a solitary retroperitoneal mass, which must be distinguished from primary retroperitoneal masses that are usually malignant. Imaging techniques are not conclusive. Definitive diagnosis is based on the postoperative pathological findings.