A bladder diverticulum is a sac that protrudes out of the bladder wall. Diverticulae may be congenital or acquired and acquired diverticula from chronic bladder outlet obstruction are commonly encountered in adults. They appear as Mickey Mouse ears on bladder ultrasound, with the bladder representing the head.
Here is an example of a large bladder diverticulum. Much larger than a typical Mickey Mouse ear!
