[A CASE REPORT: EOSINOPHILIC CYSTITIS PRESENTED WITH DEEP VEIN THROMBOSIS].

A 76-year-old man presented with gross hematuria and reported the use of anticoagulant for deep vein thrombosis (DVT). Blood tests revealed eosinophilia and thrombocytopenia. Urine cytology revealed a class I specimen with a few eosinophils in the urine. We performed cystoscopy, which revealed bladder masses with friable mucosa diffusely throughout the bladder. Magnetic resonance imaging revealed possible invasion of the bladder muscle by the masses. We performed transurethral resection of the bladder masses, and histopathological examination revealed eosinophilic infiltration of the bladder wall stroma without cancerous tissue. Therefore, the patient was diagnosed with eosinophilic cystitis.Eosinophilia and thrombocytopenia promptly resolved, and the bladder masses disappeared following the administration of prednisolone for eosinophilic cystitis. DVT also improved without recurrence of eosinophilic cystitis.