Hamartoma of the bladder in a 4-year-old girl with hamartomatous polyps of the gastrointestinal tract.

We report on a girl with hamartomatous intestinal polyps and a large mass that involved most of the posterior wall of the bladder, which on microscopic examination had the characteristics of a hamartoma. Hamartomas are among the rarest of bladder tumors. Our case is only the third reported under this designation, although 3 other cases may fall into this category. Of the 6 patients 4 have been children. Although most polypoid bladder tumors in children are rhabdomyosarcomas of the botryoid type, our case illustrates that rarely other lesions are similar grossly. Recognition of these lesions has clinical implications with regard to therapy and prognosis.