Zinner syndrome associated with concealed penis and azoospermia in an adolescent: a case report and literature review.

BACKGROUND: Zinner syndrome is a rare congenital malformation of the male urogenital system, characterized by ipsilateral renal agenesis, ejaculatory duct obstruction, and seminal vesicle cysts. Owing to its nonspecific clinical presentation, the condition is frequently underrecognized or misdiagnosed. CASE PRESENTATION: A 17-year-old male presented with a 1-month history of dysuria. Imaging studies revealed right renal agenesis and a giant posterior pelvic cyst causing compression of the urinary bladder. Semen analysis demonstrated azoospermia, while spermatozoa were successfully retrieved by percutaneous epididymal sperm aspiration, supporting a diagnosis of obstructive azoospermia. Physical examination revealed a concealed penis. Based on combined clinical, laboratory, and radiological findings, a diagnosis of Zinner syndrome was established. The patient underwent robot-assisted laparoscopic excision of the pelvic cyst. Postoperatively, urinary symptoms improved markedly, and no complications or recurrence were observed during short-term follow-up. CONCLUSION: Although Zinner syndrome is exceedingly rare, it should be considered in the differential diagnosis of pelvic cystic masses in young male patients, particularly when accompanied by ipsilateral renal agenesis, lower urinary tract symptoms, or fertility-related abnormalities. Early recognition and appropriate imaging evaluation may facilitate timely surgical intervention, symptom relief, and individualized counseling regarding reproductive potential.