IMMUNOGLOBULIN G4-RELATED DISEASE PRESENTING AS URETERAL MALIGNANCY AND URETERAL STRICTURE TREATED WITH AZATHIOPRINE AFTER SURGERY IN A GERIATRIC PATIENT WITH A SINGLE FUNCTIONAL KIDNEY: A CASE REPORT

Abstract

Immunoglobulin G4-related sclerosing ureteral disease is a rare benign disorder characterised by fibrosis and lymphoplasmacytic infiltration in the ureter. A 70-year-old man with a single functional kidney and left flank pain was diagnosed with IgG4-related ureteral disease that presented as a unilateral ureteral mass. Left hydronephrosis and a 25 × 23 × 26 mm left midureteral mass were found. No malignancy was found on ureteroscopy and urinary cytology did not reveal any neoplastic cells. A 2 cm midureteral stenosis was found in the left ureter on retrograde pyelography. It was not a ureteral stricture but was the result of periureteral inflammation and fibrosis caused by immunoglobulin G4-related sclerosing disease. Initial endoscopic ablation-obliteration therapy was unsuccessful, and after 6 weeks the patient was treated by robotic ureteroureterostomy. Most plasma cells in the excised ureteral segment were IgG4-positive. Serum IgG4 was 273 mg/dL (normal range: 85–120 mg/dL). The histology of the ureteral segment resembled retroperitoneal fibrosis and the histopathology of the stricture included IgG4-positive cells, fibrosis and ureteritis. The patient was treated with oral azathioprine for 6 months. No evidence of recurrence was seen on ureteroscopy or abdominopelvic computed tomography at the 3-month or 1-year follow-up.