Adenoma of bladder in siblings with renal dysplasia.

A huge tumor filled the lumen of the urinary bladder in a ten-year-old boy. The tumor had polypoid and papillary components with a variety of glandular structures. Some glands were surrounded by a primitive stroma reminiscent of renal dysplasia, a new finding in adenoma (or mixed hamartoma) of the urinary bladder. A couple of months later a large tumor filling the urinary bladder and with the same microscopic features was diagnosed in his fourteen-year-old brother.