Clinical and Pathological Profiles and Recurrence Risk Factors of Uterine Leiomyoma Variants：A Retrospective Cohort Study

Objective : To evaluate the prevalence and independent risk factors for recurrence following myomectomy of leiomyoma variants. Design: Retrospective cohort study Setting : Women’s Hospital, Zhejiang University School of Medicine. Population or Sample : 723 consecutive patients with confirmed variant leiomyomas (cellular, bizarre nuclei, mitotically active, etc.) treated from January 2014 to December 2024. Among these, 443 women undergoing uterine-conserving surgery were analyzed for recurrence. Methods : Medical records were reviewed for clinicopathological characteristics, surgical approaches, and follow-up data. Risk factors were analyzed using univariate and multivariate logistic regression. Cumulative recurrence rates were calculated using Kaplan-Meier analysis. Main Outcome Measures: Recurrence rate, time to recurrence, predictive risk factors, and cumulative recurrence rates at 12, 36, and 96 months. Results: Cellular leiomyoma was the most common subtype (65.0%). Recurrence occurred in 117 patients (26.4%). Of these, 51 (43.6%) required reoperation, with 34 (66.7%) undergoing hysterectomy. Two leiomyomas with bizarre nuclei recurred as sarcomas; three cellular leiomyomas progressed to disseminated peritoneal leiomyomatosis. Independent predictors of recurrence included younger age, open myomectomy, greater number of fibroids removed, increased intraoperative blood loss, and nulliparity. Pregnancy was protective. Cumulative recurrence rates were 30.7% at 12 months, 68.7% at 36 months, and 94.9% at 96 months. Conclusion: Leiomyoma variants demonstrate high recurrence rates post-myomectomy. Younger patients, open surgical approach, multiple fibroids, and significant bleeding are associated with increased risk, while pregnancy is protective. Close long-term surveillance is essential given the potential for malignant transformation.