Right-Sided Mixed Intrinsic and Extrinsic Ureteral Endometriosis Leading to a Nonfunctioning Kidney: A Case Report.

Ureteral endometriosis is a rare form of urinary tract endometriosis that may cause silent ureteral obstruction and irreversible renal damage. Mixed intrinsic and extrinsic ureteral involvement is uncommon, and right-sided disease is less frequently reported. We report the case of a 39-year-old woman with known endometriosis who presented with recurrent severe right flank pain. Imaging revealed right uretero-hydronephrosis associated with a right adnexal endometrioma and distal ureteral involvement. Diagnostic ureteroscopy could not be safely performed because of marked narrowing of the right ureteral meatus, and a double-J stent was initially placed. Renal scintigraphy subsequently demonstrated a nonfunctioning right kidney with preserved contralateral function. Definitive surgery was performed after recurrent symptoms and imaging progression documented persistent distal ureteral disease. The patient underwent laparoscopic right nephroureterectomy with open partial cystectomy and right salpingo-oophorectomy. Histopathological examination confirmed multifocal mixed intrinsic and extrinsic ureteral endometriosis associated with end-stage chronic nephritis and a right ovarian endometrioma. This case highlights the diagnostic difficulty of ureteral endometriosis, particularly when right-sided and mixed intrinsic-extrinsic disease is present, and emphasizes the importance of early functional assessment and multidisciplinary management to prevent irreversible renal loss.