PYELOCALYCEAL DIVERTICULUM

Pyelocalyceal diverticulum is a relatively uncommon condition in which there is presence of a urine containing cavity within the renal parenchyma communicating with collecting system through a narrow channel. It is usually asymptomatic. However, can present with colic, hematuria or pyuria. Calyceal diverticulum is mainly of 2 types: I. Type I- related to the minor calyx, more common, usually in the upper pole. II. Type II- communicates with the pelvis or major calyx. It is symptomatic and usually seen in midpole. The diverticulum contains milk of calcium due to stasis of urine or infection and this is what gives echogenic appearance on ultrasonography. On USG, presence of mobile echogenic material within the cyst is diagnostic. On IVU, it gets filled with contrast due to its communication with the collecting system. CT demonstrates layering of the contrast medium on delayed images which is pathognomic of calyceal diverticulum. The diagnosis is important as it is a benign condition which does not require surgical intervention.