Castleman's disease in the pararenal retroperitoneal space, which is indistinguishable from renal cell carcinoma: a case report.

A 29-year-old woman was hospitalized in our institute with the diagnosis of a right renal mass by ultrasonography on medical checkup. Computerized tomography showed a lower pole solid mass (9 cm in diameter), which was enhanced homogeneously, as well as the renal cortex in the arterial phase. The tumor was excised using radical nephrectomy based on the preoperative diagnosis of renal cell carcinoma, and thus lymph node dissection was also performed. The excised tumor was isolated from the kidney in a thin capsule, macroscopically. Postoperative pathological diagnosis revealed hyaline vascular type Castleman's disease. There was no recurrence at 1 year after the operation without any adjuvant therapy because of the complete resection.