Report of a boy with polyorchidism and a review of current knowledge regarding this unusual anomaly.

Polyorchidism is an extremely rare testicular malformation in children, and its etiology is unknown. There is an increased risk for testicular malignancy in these patients and a common association with other abnormalities, such as cryptorchidism, inguinal hernia, testicular torsion, hydrocele, and varicocele. There are insufficient data in the literature on the ideal management of polyorchidism. We report a 14-year-old boy with polyorchidism and review the current literature regarding this anomaly. Physical examination revealed a discrete, painless, left intrascrotal lump. αFP, β-hCG and LDH were normal. Scrotal ultrasound showed a well-circumscribed tissue in the left hemiscrotum measuring 2.5×2.0×1.3 cm and having the same echo-genicity as the normal testes. Color Doppler study and magnetic resonance imaging also confirmed the tissue as a third testis with its own epididymis draining to a common vas. The testis was left in situ, and the patient was managed conservatively. Polyorchidism should be considered in the differential diagnosis of all scrotal masses. The etiology of polyorchidism is thought to be accidental division of the genital ridge before 8 weeks of gestation. The cases are divided into two categories according to anatomical properties, such as having drainage to an epididymis and vas deferens. The majority of cases are mainly encountered during evaluation for the other symptoms associated. Recent evidence supports that these cases may be followed conservatively when clinical findings and imaging techniques detect no complications or suspicion for malignancy, torsion, hernia, or cryptorchidism.