Renal failure due to encrusted cystitis and pyelitis

INTRODUCTION: Encrusted cystitis and pyelitis are a rare urinary tract infection characterized by mold‐like calcification of collecting system. Here, we show a case of encrusted cystitis proceeding to pyelitis during a 1‐month delay in diagnosis. CASE PRESENTATION: A 73‐year‐old man developed hematuria and pain during micturition while he was being treated for granulomatosis with polyangiitis and lung abscess. Cystoscopy revealed calcification of the bladder wall, and an initial diagnosis of a bladder stone was made. While awaiting surgery, the bladder wall calcification extended to the renal pelvis on both sides, with renal failure. He underwent bilateral nephrostomy replacement and bladder irrigation with Solita T1 and was administered intravenous vancomycin. Calcification almost regressed after 4 weeks of treatment. CONCLUSION: Encrusted cystitis and pyelitis should be suspected if the patient shows alkaline urine and urothelial mucosa calcification. Appropriate treatment includes antibiotics, urine drainage, and chemolysis by bladder irrigation.