[Brunn's nests as a cause of benign tumor of the bladder in children].

This report concerns the case of a male patient admitted for an operation due to vesicoureteral reflux. During the operation a sessile tumor was discovered in the interior of the bladder at the level of the neck. The tumor corresponded histologically to a mucous polyp with Brunn's nests in the interior. The following are commented on: the extreme rarity of the case, the histopathological characteristics of this abnormal epithelial proliferation which is produced as an exaggerated response to an irritative stimulus and its non-malignant nature.