[Proteus syndrome: Case report of bladder vascular malformation causing massive hematuria].

Proteus syndrome is a rare, sporadic disorder consisting of disproportionate overgrowth of multiple tissues, vascular malformations, and connective tissue or epidermal nevi. Due to mosaic pattern of distribution, the phenotypes are variable and diverse. Vascular malformations are part of the major criteria used to define and diagnose this syndrome. It can involve the gastrointestinal tract, spleen, or the urinary tract but bladder malformations are rare. We report here a case of bladder vascular malformation in a 12-year-old boy known to have Proteus syndrome and review the literature on bladder malformations or tumors in this syndrome.