(452) Adult Cryptorchidism in the 21st Century: A Systematic Review of Research Articles Based on Malignancy Risk, Reproductive Outcomes, and Hormonal Disruption

Introduction Regarding optimal management of patients with uncorrected cryptorchidism (UC) in adulthood, the respective guidelines are less clear. Objective To further support the decision-making process of the patients and to expand the evidence base that is available for the clinicians. Methods The systematic review was registered to PROSPERO (CRD420251119301) and PRISMA guidelines were followed. Electronic databases PubMed/MEDLINE, Scopus and Web of Science were scanned and research articles published between January 2000-August 2025 and that evaluated malignity and/or spermatogenesis and/or hormonal assessment outcomes of adult patients with UC were included in the systematic review. The following search terms were utilized: “Adult” OR “postpubertal” AND “undescended testis” OR “undescended testicle” OR “cryptorchidism” OR “orchidopexy”. Results 22 studies with 1003 patients with an age range of 18–74 years, met the inclusion criteria and were included in the systematic review. Out of fifteen were cohort studies, while the remaining seven were cross-sectional in design. Data on malignancy/premalignancy status at initial presentation was provided in 753 testes included in 16 studies and identified in 11 testes (1.5%), including six cases of germ cell neoplasia in-situ and five cases of seminoma. Pooled rate of malignancy/premalignancy was higher in intra-abdominal undescended testes (2.0%) compared to inguinal undescended testes (0.04%) (p=0.042). Three studies reported malignancy outcomes during the follow-up period in patients who had undergone orchidopexy for UC. During a follow-up period ranging from 7 to 132 months, no cases of malignancy were identified. Ten studies reported initial semen analysis results of 277 patients. In patients with unilateral UC, normal semen parameters were reported in 85 (48%), oligo/asteno/teratozoospermia in 55 (31.1%), and azoospermia in 37 (20.9%). All patients with bilateral UC were azoospermic. Four studies evaluated patients who underwent orchidopexy for UC in terms of improvement in semen analysis findings during the follow-up period. Among 58 patients, improvement in semen analysis findings was observed in 4 (6.9%). 32 patients who underwent orchidopexy for bilateral inguinal UC were azoospermic. During a follow-up period of 8–36 months, presence of sperm in the postoperative ejaculate was documented in 3 patients (9.4%). Sperm retrieval rate was 68.2% (15 patients) in unilateral cryptorchidism and 20% (4 patients) in bilateral cases (p=0.006). None of eight intra-abdominal undescended testes yielded spermatozoa on subsequent TESE/mTESE. Hormone profile alteration data following orchidopexy was provided in four studies. Three studies reported no significant change in total testosterone. A significant increase in total testosterone levels was observed in one study. Hormonal profile alterations were evaluated following orchiectomy for unilateral cryptorchidism in 40 patients in one study, and a significant decrease in total testosterone levels was observed in 7 patients (17.5%). Conclusions Malignancy risk in adult cryptorchidism is highest in intra-abdominal testes, supporting orchiectomy as preferred option in these cases. In unilateral cases, semen parameters are often preserved, whereas bilateral cases are almost always azoospermic; however, orchidopexy might still provide a limited chance of sperm recovery and paternity. Hormonal effects of surgery are generally minimal. These findings emphasize the need for individualized management to guide treatment algorithms. Disclosure No