Perinatal testicular torsion: ultrasound assessment and differential diagnosis.

Perinatal testicular torsion, defined as torsion occurring in the prenatal period or in the first month after birth, accounts for 10% of all cases of testicular torsion in pediatric patients. Most are extravaginal, and intravaginal torsion is rare. Its management is controversial, due to the low viability of the testis and the possibility of bilateral torsion. Ultrasonography is the method of choice to study testicular torsion. Combining B-mode and power Doppler imaging facilitates a fast reliable diagnosis. We review the ultrasonographic appearance of neonatal testicular torsion for each presentation, the differential diagnosis with other causes of increased scrotal volume in neonates, and its treatment.