Unusual cause of obstructive uropathy.

We report a case involving a 55-year-old healthy man that presented with urinary retention and a lower abdominal mass. His evaluation revealed a large mucocele arising from the appendix that caused severe bilateral ureteral obstruction and renal failure. Appendiceal mucoceles are rare and insidious entities that can present with urologic manifestation. Despite their rarity, this case highlights the importance of including mucoceles in the differential diagnosis in cases involving ureteral obstruction caused by external compression.