Evaluation of histologic images of the testes of prepubertal boys and of puberty who underwent surgery for cryptorchidism OBJECTIVES: To evaluate histological traits of testes in boys with retained, descended, and ascending testes. Evaluate tissue damage based on age and correlation with germ cell loss. Investigate the link between maternal and child epidemiological data and the presence of retained and mobile testes in boys. STUDY DESIGN: A cross-sectional study with historical data. PARTICIPANTS AND METHODS: The study evaluated boys who underwent surgery between 2018 and 2023 at the Department of Pediatric Surgery, Clinical Hospital Center Osijek, due to retained testes. RESULTS: The study involved 178 boys with retained testes; 75.2 % aged 2 to 7 years. Gestational age ranged from 27 to 42 weeks, birth weight from 660 g to 5210 g. Maternal age ranged from 19 to 43 years. A statistically significant difference in interstitial fibrosis presence was noted between boys younger and older than seven years, with higher prevalence in the older group. CONCLUSION: Different clinical aspects of cryptorchidism in boys provide valuable insights for clinical practice. Assessment of the tubular fertility index can help predict fertility in boys with cryptorchidism, while monitoring birth weight and gestational period can identify at-risk groups. Detection of interstitial fibrosis provides important information about the lack of germ cells in the testes, crucial for diagnosis and treatment planning. Although without statistically significant differences, the presence of interstitial fibrosis suggests the need for monitoring testicular health in boys. Variations in the extent and severity of interstitial fibrosis provide insights into different pathological processes among different types of cryptorchidism. Finally, the higher incidence of interstitial fibrosis in older boys highlights the need for early detection and intervention in cryptorchidism. Cryptorchidism; Fertility; Germ cells; Leydig cells; Orchiopexy