Two cases of vasculitis of the urinary bladder: diagnostic and pathogenetic considerations

Vasculitis involving the urinary bladder is rare and difficult to diagnose. Organ-isolated vasculitis challenges pathogenetic theories.

A human immunodeficiency virus- and hepatitis B virus-infected man with hematuria and a mass lesion was initially given a clinicopathologic diagnosis of bladder hamartoma. Over 11 months, without immunosuppressive therapy, there were multiple "recurrences" of the tumor with progressive distal ureteral obstruction, but no evidence of systemic vasculitis. Polyarteritis nodosa-like vasculitis with positive immunostaining for hepatitis B surface antigen in urothelium and vessels was found on review. A second patient, presenting with signs and symptoms suggesting transitional cell carcinoma in situ, was found to have small vessel vasculitis.

Bladder vasculitis should be considered in the differential diagnosis of neoplasia. Extrahepatic hepatitis B virus infection may be related to the organ specificity in some cases of vasculitis.