A Rare Cause of Unilateral Hydronephrosis

Endometriosis is charactherized with existing of endometrial cells outside of uterus. Endometriosis usually effects ovaries, fallopian tubes and uterine ligaments. It rarely places on ureter. We presented a 42 year-old female patient with lumbar pain and dysuria referred to our clinic. Urinary sediment showed microscopic hematuria and imaging studies with left renal hydronephrosis. Projecting into the lumen of the ureter showed a mass in the diagnostic ureterorenoscopy. We performed distal ureterectomy and ureteroneocystostomy in the treatment of ureteral mass. Microscopic evalution of the ureteral mass showed endometriosis. Endometriosis should be considered as a rare cause of hydronephrosis in female patients with an undetectable stone in imaging studies.