[Pyelocalicial diverticula].
OBJECTIVE: To review the embryological and clinical aspects of the different types of pyelocaliceal diverticula, with special reference to the differential diagnosis and treatment. METHODS: Images of type I and II pyelocaliceal diverticula are shown. The conditions that cause difficulty in making the differential diagnosis are discussed. RESULTS: Urography continues to be the diagnostic method preferred and is sometimes aided by retrograde ureteropyelography. CONCLUSIONS: Pyelocaliceal diverticula are cystic eventrations of the upper urinary tract lying within the renal parenchyma that communicate through a narrow channel into the main collecting system. They occur in 0.2 to 0.5% of the population and are congenital in origin. Calyceal diverticula are frequently found incidentally on routine excretory urograms, but patients may complain of flank pain, hematuria or recurrent urinary infections. In the past, treatment required open renal surgery. Endourologic procedures are widely utilized today.