Brunn's Cyst Inducing Persistent Lower Urinary Tract Symptoms in a Young Man: A Case Report.

Lower urinary tract symptoms (LUTS) are mostly caused by hyperplasia of the prostate in the elderly generation or are the consequence of a urethral stricture in young men. Proliferated Brunn's cell nests forming cysts at the bladder neck can likewise result in similar symptoms and can, therefore, often be overlooked. The case describes a 46-year-old man presenting with the typical LUTS of urgency and pathologic residual urine volume of 350 mL. Sonographic and cystoscopic diagnostics showed a cystic lesion located at the bladder neck, acting as a ball valve mechanism. Transurethral deroofing and resection of the cyst resulted in an immediate resolution of LUTS and a symptom-free patient with no residual urine at follow-up. The presence of a Brunn's cyst is rare but should be kept in mind as a differential diagnosis of LUTS in young men.