Colovesical fistula an unusual complication of cytotoxic therapy in a case of non-Hodgkin's lymphoma

A 65-year old man, a known case of non-Hodgkin's lymphoma of base of the tongue and epiglottis presented with complaints of penumaturia and faecaluria. He had received the first cycle of cytotoxic therapy (CHOP-regimen). At the end of the cycle he developed febrile neutropenia (circulating granulocyte count <1500/mm³). Cystogram showed air in the bladder area and a fistulous communication to a cavity behind the bladder. CT-scan showed air in the bladder, a fistulous communication between the sigmoid colon and bladder along with an intervening small abscess cavity. On exploration a fistulous communication between the sigmoid and bladder along with an intervening small abscess cavity was found Resection of involved portion of sigmoid and end to end anastomosis along with a diverting colostomy was done. The bladder was closed in two layers with an omental interposition between it and the sigmoid along with a suprapubic cystostomy. The histopathology demonstrated only inflammatory response without any evidence of malignancy or diverticular disease.