To evaluate the clinical data, ultrasonic features, treatment, and long-term outcome of transverse testicular ectopia (TTE) in children.

Children with TTE were enrolled in the study between November 2009 and August 2019 in Shenzhen Children's Hospital in China. Clinical information, including demographic characteristics, clinical manifestations, TTE-associated anomalies, ultrasonographic findings, and surgical procedures, were collected from all patients. Patients were re-evaluated at the end of 4 weeks and 6 months after the operation.

A total of 16 cases were enrolled and underwent surgeries, all patients had undescended testis with contralateral inguinal hernia. The ultrasonic findings showed two testicles in 15 cases and no testes in 1 case. Müllerian ducts remnants were found by laparoscopy in 6 cases or by ultrasound in one case. Sixteen cases were treated with laparoscopy orchidopexy or laparoscopy assisted trans-septal orchidopexy-inguinal exploration. After surgery, 16 patients had both testicles in an orthotopic position and with equal size, with normal blood flow.

TTE should be suspected in patients with nonpalpable undescended testis and contralateral inguinal hernia. The contralateral processus vaginalis sac occurs in all cases of TTE. Ultrasonography is essential for an early diagnosis of TTE. Laparoscopy-assisted surgery is safe, effective, and minimally invasive therapy for TTE.