Zinner Syndrome: An Overlooked Congenital Anomaly in Male Reproductive Health - A Case Report

Abstract Zinner Syndrome, a rare congenital anomaly, involves unilateral renal agenesis, ipsilateral seminal vesicle cysts, and ejaculatory duct obstruction due to mesonephric duct maldevelopment. With approximately 200 reported cases, it typically presents in young adulthood with pelvic pain, urinary symptoms, or infertility. A 22-year-old male presented with vague abdominal discomfort and occasional lower abdominal pain. Ultrasound revealed left renal agenesis, compensatory right kidney hypertrophy, mild hepatomegaly with fatty changes, and a midline prostatic cyst, initially considered a prostatic utricle cyst. MRI confirmed a bi-loculated left seminal vesicle cyst, dilated left ejaculatory duct and vas deferens, and absent left kidney, establishing Zinner Syndrome. Resulting from embryologic mesonephric duct anomalies, Zinner Syndrome is diagnosed via ultrasound and MRI, with MRI offering superior anatomical detail. Management varies from conservative observation for mild symptoms to surgical intervention for pain or infertility. This case underscores the need to consider Zinner Syndrome in young males with renal agenesis and pelvic cysts, even with atypical symptoms like abdominal discomfort. Early imaging-based diagnosis of Zinner Syndrome is critical to guide management and prevent complications such as infertility. This case highlights the importance of clinician awareness to include this rare condition in the differential diagnosis for young males with relevant imaging findings.