Eosinophilic Cystitis Presented as a Manifestation of Hypereosinophilic Syndrome: A Case Report and Review of the Literature

Background: Hypereosinophilic syndrome (HES) is a group of disorders marked by the sustained overproduction of eosinophils, in which eosinophilic infiltration and inflammatory substance release cause damage to multiple organs. Eosinophilic cystitis (EC) is an inflammatory disorder caused by eosinophilic infiltration of the bladder wall. Although EC is often associated with eosinophilia, it has been rarely reported as a manifestation of HES. We report a case of EC as a primary manifestation of HES. The patient was a 27-year-old male with a history of complete intracardiac repair of tetralogy of Fallot who presented with an acute onset of dysuria accompanied by eosinophilia (7.5 × 103/µl, 60% of white blood cells). Ultrasonography and MRI of the bladder showed a bladder mass, a biopsy of which revealed eosinophilic infiltration and degranulation. Methods: We performed a literature search in PubMed from 2001 to 2012 to find patients with EC who may have had HES. Results: There were 4 patients with HES who had EC including the present case. Of 14 patients reported as EC in whom the eosinophil count was described, 5 had eosinophils of ≥1,500/µl. None of the 5 patients had secondary causes for eosinophilia. Of the 9 patients with definite or probable HES, 7 patients (78%) were male and 5 patients (56%) showed a concomitant eosinophilic gastrointestinal disorder. Conclusion: HES may not be uncommon as the cause of EC. Thorough evaluation and close monitoring are warranted in EC patients with elevated eosinophils.