The Natural History of Retractile Testicle(s) and Progression to Orchiopexy

PURPOSE: To evaluate the incidence of testicular ascent and orchiopexy among boys with a history of retractile testicle(s). METHODS: A single-institution review identified boys diagnosed with retractile testicle(s) from 1/1/18 to 7/30/2020. Identified patients were prospectively followed until age 15 or 3/31/2025 by reviewing records from the state's two major hospital systems. Boys with unreliable exams or planned orchiopexy at diagnosis were excluded. Cumulative incidence curves were generated, and survival analyses were performed on those with ≥6 months of follow-up. RESULTS: Overall, 498 boys had 824 retractile testicle(s) diagnosed by pediatric urologists. After excluding boys with ≤6 months of follow-up, a final cohort of 237 boys with 391 retractile testicle(s) was diagnosed at median age 4 years. Testicular ascent occurred in 51 boys (47%, cumulative incidence by 84 months from diagnosis [95% CI 32-64]) at median age 7.3 years. Ascent was associated with BMI (sHR 0.86 [95% CI 0.76-0.97]) and right-sided laterality compared to bilaterality (sHR 3.63 [95% CI 1.76-7.50]). A total of 66 boys (57%, cumulative incidence by 84 months from diagnosis [95% CI 43-72]) underwent or were scheduled for orchiopexy for ascent (77%), torsion (9%), patient factors limiting examination (9%), or pain (5%). Only 69% of boys seen in our system had a testicular examination documented at a well-child visit. CONCLUSIONS: Within our cohort, the estimated cumulative incidence of ascent or orchiopexy by 84 months from diagnosis was 47-57% among boys with retractile testicle(s). These findings highlight the importance of long-term surveillance by a pediatric urologist.