Prenatal testicular torsion: diagnosis and natural course. An ultrasonographic study.

The aim of this study was to demonstrate the ultrasonographic features of prenatal torsion of the testis at presentation and during follow-up, with histological correlation post-orchidectomy. Between January 1985 and December 1999, 13 neonates with antenatal torsion of the testis were examined postnatally, at presentation and during follow-up, with high-resolution ultrasonography, including colour Doppler ultrasonography. Bilateral testis volume was evaluated [lengthxwidthxdepthx(pi/6)]. Ultrasonographic findings were correlated with histological findings (n=8) and findings at surgery. Moreover, in 1 patient the affected testis was postoperatively examined with ultrasonography in vitro. These findings were correlated with preoperative ultrasonography and corresponding histological slices. All patients (n=13) presented with a painless congenital scrotal mass. On the affected side no flow was found with colour Doppler ultrasonography. Testis volume on the affected and normal side showed mean values of 2.1 and 0.5 cc, respectively. On ultrasonography all patients showed scrotal swelling and a heterogeneous testis with hypoechoic central areas (necrosis). The tunica albuginea was thickened in all patients, with focal (n=2) or rim-like (n=11) hyperechoic reflections (calcifications) at the transitional zone between testis and tunica albuginea. In 9 patients follow-up ultrasonography showed progressive testis atrophy on the affected side. In 10 patients a contralateral hydrocele was found. Prenatal torsion shows a characteristic ultrasonographic pattern. In newborns with a scrotal mass, these ultrasonographic findings should suggest this diagnosis and delay in immediate surgery and/or oncological work-up may be appropriate.