Eosinophilic cystitis simulating recurrence of an aggressive urothelial cancer

To describe a case of eosiniphilic cystitis diagnosed during follow-up for bladder cancer.

Based on the suspicion of a bladder fibrous tumor, the patient was submitted for partial cystectomy.

The histological analysis revealed eosinophylic cystitis and the patient completed a 3-month course of antihistamines. 35 and 31 months, respectively, after the diagnosis of high grade papillary urothelial carcinoma and eosinophilic cystitis the patient remains asymptomatic and without evidence (clinical or imaging) of recurrent disease.

Eosinophilic cystitis is a rare disease. The clinical, imaging and cystoscopy findings are nonspecific, so its diagnosis is histological. Although its pathogenesis is not yet fully understood, the association between eosinophilic cystitis and bladder cancer is already known.