Sjögren's syndrome with hydronephrosis caused by pseudolymphoma.

A 67-year-old woman with Sjögren's syndrome was found to have left hydronephrosis and stenosis of the left ureter. Exploratory laparotomy disclosed a nodule at the ureteropelvic junction of the left ureter. Histopathological examinations of the biopsied specimen of this nodule showed lymphoid hyperplasia within the ureteral wall. Low dose prednisolone improved hydronephrosis and pseudolymphoma within several months. Hydronephrosis secondary to pseudo-lymphomatous infiltration of the ureter is a rare but, if properly treated, reversible complication of Sjögren's syndrome.