The value of ultrasonography in boys with a non-palpable testis

Abstract

Background: In patients with a non-palpable testis (NPT) on physical examination, the testis is assumed either to be situated intra-abdominally or to be hypoplastic or absent. Diagnostic laparoscopy in these boys is considered the preferable first step. In this study the diagnostic value of pre-operative ultrasound for NPT is assessed in comparison with laparoscopy.

Methods: All boys aged under the age of 17 years who were diagnosed with an NPT by a pediatric surgeon from 2000 till 2012 were evaluated. All patients of whom clinical, ultrasonographic, and operative findings were available were included.

Results: Ninety-six boys with 117 NPTs were included. With ultrasound 67 testes were detected in the inguinal canal, which was confirmed peroperatively for 61 testes. Of the 15 testes with an intra-abdominal position on ultrasound, 10 were found intra-abdominally during surgery. The positive predictive value of the ultrasonography is 91% for inguinally located testes and 67% for intra-abdominally located testes.

Conclusion: Ultrasonography has a high positive predictive value for inguinally located testes. When ultrasound locates a testis in an inguinal location, a primary inguinal exploration can be considered, preventing an unnecessary diagnostic laparoscopy.

Keywords: Diagnostic laparoscopy; Inguinal exploration; Non-palpable testis; Ultrasound.