Primary bladder diverticula are not common (incidence of 1.7%) and are a congenital malformation.
A bladder diverticulum is a herniation of bladder mucosa through the bladder wall. Large
diverticula can act as paradox reservoir during bladder voiding. Post-void residual urine and urine
stasis can result in chronic urinary tract infection, stone formation and malignant urothelial transformation
(i.e. TCC). Therefore diverticula, especially in those with a narrow neck, should be
carefully examined during cystoscopy.