Eosinophilic cystitis presenting as invasive bladder cancer: comments on pathogenesis and management.

Eosinophilic cystitis is a rare bladder lesion that usually presents with hematuria and has the cystoscopic appearance of a bladder tumor. Ten cases (only 4 adults) have been reported in which this disease has presented with a palpable mass. We report a case in which the lesion presented as an invasive bladder tumor with a palpable mass in an adult and comment on the possible etiology.