Villous adenoma of the urinary bladder with imaging findings suggestive of enterovesical fistula: A case report.

Villous adenomas of the urinary bladder are rare epithelial neoplasms with malignant transformation potential, exhibiting histological features similar to their gastrointestinal counterparts. Their low prevalence has hindered clinical characterization and differential diagnosis from other malignant bladder entities. We present the case of a 63-year-old woman with a history of cardiovascular and metabolic diseases who was admitted for acute urinary obstruction and hematuria. Imaging studies revealed a bladder mass and imaging findings suggestive of a possible enterovesical fistula, although no direct evidence was identified. Cystoscopy identified a 6 cm vegetative lesion in the bladder trigone, which was completely resected trans-urethrally. Histopathological and immunohistochemical analyses confirmed the diagnosis of villous adenoma of the bladder, with positive staining for CK-20 and CDX-2. The patient had a favorable postoperative course. Although rare, villous adenoma of the bladder should be recognized due to its malignant potential and the need for close postoperative surveillance. This case report contributes to the growing body of knowledge regarding this entity in female patients.