Obstructing ureteral calculus causing massive hydronephrosis in a renal allograft.

Nephrolithiasis is a rare complication of renal transplantation. Patients with an obstructing calculus in a renal allograft often lack the usual renal colic symptoms, and therefore present with atypical symptoms. Treatment of obstructing calculi is imperative to prevent renal allograft failure and other complications. We report the case of a 46-year-old man who presented 28 years after renal transplant with renal failure and massive hydronephrosis secondary to an obstructing calculus.