[A case of eosinophilic cystitis with retroperitoneal neurinoma].

A 63-year-old female visited our department, complaining of miction pain. She had several episodes of urinary occult blood. Urinalysis included a small number of red cells, white cells and bacilli. Physical examination revealed a fist-sized mass of her right flank. Cystoscopic examination showed a botryoid tumor with multiple erythematous raised plaques. Biopsy was reported as massive infiltration of eosinophiles in submucosal layer of the bladder, i.e. eosinophilic cystitis. Antibiotics were effective for the improvement of urine findings and symptoms within a week. IVP and CT revealed the abdominal mass as a retroperitoneal tumor with cystic degeneration, and the tumor was resected. Pathological diagnosis was benign neurinoma. Both eosinophilic cystitis and retroperitoneal neurinoma are rare, and the concurrent occurrence of these two diseases has not been reported. Recent studies have suggested that eosinophilic cystitis may occur more frequently than suspected, and may be overlooked clinically and microscopically. This uncommon form of cystitis should be considered in the differential diagnosis especially when the patient has unexplained episodes of bladder symptoms and hematuria.