Severe refractory infection due to renocolic fistula in a patient with a giant kidney and ADPKD undergoing long-term hemodialysis

Renocolic fistula is rare. Renal cyst infection is a serious complication in patients with autosomal dominant polycystic kidney disease (ADPKD). We present a case of refractory renal cyst infection due to renocolic fistula in a patient with ADPKD. A 65-year-old man with ADPKD on hemodialysis visited our hospital with complaints of fever and left abdominal pain. We diagnosed renal cyst infection with abdominal computed tomography scans. After hospitalization, gas shadow was observed in the left renal cyst. Percutaneous puncture of the cyst was performed. Because contrast medium into the left renal cyst through nephrostomy was flowing into the descending colon, renocolic fistula was diagnosed. The patient underwent nephrectomy combined with partial descending colonic resection and splenectomy, but he died. Renocolic fistula is probably hidden in some refractory renal cyst infection cases. This case report aims to create awareness of renocolic fistula, so that early diagnosis and intervention can salvage such patients.