Diagnostic Effectiveness of Contralateral Testicular Hypertrophy in Children with Non-Palpable Testicles.

PURPOSE: To evaluate the effectiveness of contralateral testicular volume measurements in differentiating monorchidism from intra-abdominal viable testes in children with non-palpable testes (NPt). MATERIALS AND METHODS: The data of 179 patients who underwent surgery for undescended testes between January 2017 and January 2024 were retrospectively reviewed. The study included 33 patients with unilateral non-palpable testes. Testicular volumes were measured by ultrasonography 6-12 months prior to diagnostic laparoscopy, and the surgical findings were recorded. RESULTS: Diagnostic laparoscopy was performed on 33 children with non-palpable testes. For five patients, staged orchiopexy was planned due to the testes being 2 cm or more away from the internal inguinal ring. In 22 patients, inguinal orchiopexy was performed as the testes were around the internal inguinal ring (AIR). In the remaining six patients, no testes were found; the spermatic cord and vessels terminated at the internal inguinal ring (vanishing) or were atrophic (nubbin). There was a significant difference in the contralateral testicular volumes between patients with vanishing testes and those with intra-abdominal viable testes (p < 0.001). Additionally, there was a statistically significant difference in the contralateral testicular volumes between the AIR group and those with testes remote from the internal inguinal ring (RIR) (p = 0.03). CONCLUSION: The preoperative ultrasonographic measurement of the contralateral testicular volume in children with a unilateral non-palpable testis can provide valuable information about the nature of the intra-abdominal testis. The presence of a hypertrophic contralateral testis can guide surgeons prior to laparoscopy and is valuable for counseling parents about potential diagnoses.