2 CASES OF VASCULITIS OF THE URINARY-BLADDER - DIAGNOSTIC AND PATHOGENETIC CONSIDERATIONS

Background.-Vasculitis involving the urinary bladder is rare and diffi cult to diagnose. Organ-isolated vasculitis challenges pathogenetic th eories. Methods and Results.-A human immunodeficiency virus- and hepat itis B virus-infected man with hematuria and a mass lesion was initial ly given a clinicopathologic diagnosis of bladder hamartoma. Over 11 m onths, without immunosuppressive therapy, there were multiple ''recurr ences'' of the tumor with progressive distal ureteral obstruction, but no evidence of systemic vasculitis. Polyarteritis nodosa-like vasculi tis with positive immunostaining for hepatitis B surface antigen in ur othelium and vessels was found on review. A second patient, presenting with signs and symptoms suggesting transitional cell carcinoma in sit u, was found to have small vessel vasculitis. Conclusions.-Bladder vas culitis should be considered in the differential diagnosis of neoplasi a. Extrahepatic hepatitis B virus infection may be related to the orga n specificity in some cases of vasculitis.