[A case of soft renal calculi with xanthogranulomatous change].

A case of soft renal calculi with xanthogranulomatous change is reported. A 37-year-old female visited our hospital on February 4, 1992 complaining of frequency of urination and right lower abdominal pain. Under the clinical diagnosis of right renal calculi, extracorporeal shock wave lithotripsy was attempted, but no sign of destruction was observed. Right pyelolithotomy was performed on June 8, 1992. Several soft calculi were removed from the right renal pelvis. Microscopic examination showed that the calculi were surrounded by a cell layer including foam cells and giant cells. In addition, the calculi revealed positive reaction by several stainings (alcian-blue, PAS and muticarmin), which showed that the calculi were mainly composed of mucopolysaccharides. We discussed this disease in terms of symptoms, diagnosis, treatment and mechanism in comparison with previous reports.