[Challenging Case of Primary Renal Castleman's Disease Accompanied with Bacterial Pyelonephritis].

Castleman's disease is a rare lymphoproliferative disease, mostly found in the mediastinum. The number of Castleman's disease cases involving the kidneys is still limited. We report a case of primary renal Castleman's disease sporadically detected during a regular health check-up as pyelonephritis with ureteral stones. In addition, computed tomography showed renal pelvic and ureteral wall thickening with paraaortic lymphadenopathy. A lymph node biopsy was performed, but it did not confirm either malignancy or Castleman's disease. The patient underwent open nephroureterectomy for diagnostic and therapeutic purposes. The pathological diagnosis was renal and retroperitoneal lymph node Castleman's disease with pyelonephritis.