Giant obstructing calculus in the distal ureter secondary to obstruction by a ureterocele.

A 43-year-old man presented with bilateral simple ureteroceles complicated by calculi. A huge left ureteral calculus subsequently developed, causing nonfunctioning of the left kidney. This is apparently the largest calculus associated with an orthotopic ureterocele ever reported in the literature. Its cause, diagnosis, and treatment are discussed.