RESUMO
Spontaneous partial rupture of upper renal tract is rare and is usually associated with urolithiasis. Other causes include instrumentations, trauma, pelvic cancer, retroperitoneal fibrosis, fluid overload, and pregnancy. We report two cases (46-year-old and 41-year-old men) of upper renal tract rupture. The first case had rupture of the ureter proximal to stone impaction and the second case had fornicial rupture secondary to stone impaction at the uretero-vesical junction. In contrast to ureteral rupture, fornicial extravasation is more common and the symptoms are always mild. The mechanism of ureteral rupture can be explained as either pressure around the ureteral wall due to stone impaction, or a tear caused by pressure during the passage of the stone. Fornicial rupture occurs when intra-pelvic pressure is greater than 35cm H2O. It is important to distinguish true rupture of the ureter from fornicial tear with extravasation, because both the outcome and treatment are different.