Congenital diverticulum of the bladder mimicking tumour.

The incidence of bladder diverticula is low and identification is usually straightforward with contrast studies. We present a case of a child who had a clearly identified bladder diverticulum as well as a soft-tissue lesion in the posterior wall of the bladder that was suspected to be a rhabdomyosarcoma. Despite ultrasound scanning, micturating cystourethrogram, computed tomography and cystoscopy, open surgery was required to rule out tumour.