title: Arteriovenous Malformation Masquerading as a Bladder Tumor. A Case Report.
abstract: BACKGROUND
  Arteriovenous malformation (AVM) of the urinary bladder is an extremely rare benign vascular lesion. The clinical significance of bladder AVM lies in its presentation with painless hematuria and a hyperemic sessile bladder wall mass.
  
  
  METHODS
  A 47-year-old man presented with irritative symptoms and hematuria. Cystoscopically the lesion appeared as an erythematous, broad-based mass obscuring the right ureteral orifice. The patient underwent cystoprostatectomy for suspected mass lesion. Histologically the bladder tumor was composed of numerous malformed blood vessels of various calibers with myxoid degeneration. Immunohistochemically the bland endothelial cells lining in the vessels were reactive for markers of CD31 and CD34. Ki67 index was < 1%. The patient was free of disease 24 months after surgery.
  
  
  CONCLUSIONS
  Our findings broaden the morphologic spectrum of bladder arteriovenous malformation and emphasize its deceptive presentation.
authors: Quan
authors: Q
authors: Zhou
authors: Hong
authors: H
authors: Chang
authors: Lei
authors: L
authors: Yang
authors: Jixin
authors: J
authors: Zhang
authors: Hongyu
authors: H
authors: Zhao
authors: Lisha
authors: L
authors: Wang
authors: Antonio
authors: A
authors: Lopez-Beltran
authors: Rodolfo
authors: R
authors: Montironi
authors: Darrell D
authors: DD
authors: Davidson
authors: Liang
authors: L
authors: Cheng
mesh_terms: D001165:Arteriovenous Malformations / Q000175:diagnosis / Q000473:pathology*; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D008875:Middle Aged; D011468:Prostatectomy / Q000379:methods; D001745:Urinary Bladder Diseases / Q000473:pathology*; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis / Q000473:pathology*