Eosinophilic cystitis and membranous nephropathy: a rare case

Eosinophilic cystitis (EC) is a rare, non-infectious inflammatory bladder disease that mimics malignancy and is diagnosed histopathologically. We report a 53-year-old male patient with a history of membranous nephropathy in remission, who presented with sudden onset gross hematuria and dysuria. Imaging revealed a bladder wall lesion, which was resected transurethrally. Histopathology confirmed EC. The patient was treated symptomatically and recovered without complications. No recurrence was observed during follow-up. The patient did not require corticosteroids or antibiotics and remained asymptomatic during 6 months of follow-up. This case underscores the importance of considering EC in patients with hematuria, especially those with underlying nephropathy.