INDUCTION OF EXPERIMENTAL LEIOMYOMA IN SMALL RODENTS: a systematic review

Background: Uterine leiomyomas (LU) are one of the most common gynecological diseases, where the ideal clinical treatment is yet to be developed, and many cases are subjected to invasive procedures, justifying the research of new clinical treatments and preclinical research is essential. Small rodents are the species most used in scientific studies.Objective and rationale: This study aimed to conduct a systematic review to investigate the main methods of LU induction and the verification method, as well as the advantages and disadvantages of each method in small rodents. Leiomyomas predominantly affect the uterus in women of reproductive age, representing a significant public health concern due to the impact on quality of life, fertility and costs related to treatment. Conducting a study on leiomyoma induction is justified by the need to better understand the biological and molecular mechanisms involved in developing this condition. Experimental models in small rodents offer a controlled platform to study etiological, genetic and environmental factors associated with leiomyoma formation, also allowing the evaluation of new pharmacological therapies or preventive interventions efficiently and ethically.Search methods: The search was conducted between November 2024 and December 2025 in the PubMed, SciELO and Embase databases. For the search, the terms induced leiomyoma, myoma, uterine fibroids and smooth muscle tumors, rat, rodent, mouse, mice and murine were used, combined with Boolean operators AND and OR.Outcomes: After applying the inclusion criteria and careful analysis, articles identified 39 complete studies that satisfactorily addressed the topic. In total, 1064 rats and 376 mice were analyzed, where most of the studies (n = 30) involved hormonal induction alone or in association with other methods. Most of the articles (n = 20) did not inform how experimental leiomyoma induction was confirmed. Among the studies that confirmed it, evaluation with a digital caliper was the most common approach (n = 7).Wider implications: In the induction of experimental LU, the models used were transgenic, hormonal induction, monosodium glutamate, ischemic injury, external stimulus, cell transplantation with the ELT-3 lineage and xenotransplantation in tissue and cell form. The inductions were evaluated by macroscopy, microscopy, and ultrasound. In some studies, it was unclear. We observed the need for a consensus on the standard model for developing and evaluating LU induced in mice or rats so that the studies can be reproduced and compared more indisputably. This study may contribute to disseminating and selecting the most appropriate method for future research on new experimental treatments for LU.