Zinner syndrome in childhood and adolescence: Report of four cases and review of the literature.

Zinner syndrome is a rare congenital malformation of the urinary system that occurs exclusively in males. It consists of renal agenesis, ipsilateral obstruction of the ejaculatory duct, and cystic changes in the seminal vesicles. It is rarely described in the pediatric population due to the absence of symptoms, as well as the failure to recognize it due to masking by other morphological changes and conditions. Four patients from the pediatric population are presented. Two patients were asymptomatic, and the changes were detected incidentally or during other diagnostic procedures. The other two patients exhibited symptoms and signs such as testicular pain, abdominal pain, hematuria, and hematospermia, along with megaureter. Ultrasound serves as the initial diagnostic method, while confirmation of Zinner's syndrome is established by MR urography. In cases that ultrasound verified kidney agenesis and ipsilateral anechoic, avascular tubulocystic structures, it is necessary to perform follow-up MR urography to confirm or exclude Zinner's syndrome. Following diagnosis, asymptomatic pediatric patients should be monitored every 6 months to a year, using ultrasound, with particular attention to cyst size and content.