Why does my medical report say possible of calyceal diverticulum? what does that mean? doc doesn't seem to be overly concerned about it.

Usually asymptomatic: Calyceal diverticulum is a relatively uncommon cyst-like lesion , often discovered incidentally during ultrasound examination of the kidneys. Calyceal diverticulum communicates with the collecting system through a narrow channel. Sometimes can be symptomatic owing to recurrent urinary tract infection (UTI) or stone formation within the diverticulum, both of which related to stasis.