Characteristics that distinguish leiomyoma variants from the ordinary leiomyomas and recurrence risk

Aims:To evaluate the clinical characteristics that distinguish the leiomyoma variants from the ordinary ones, as well as the recurrence risk and patterns of these tumors.Methods:This retrospective, case-control study included women diagnosed with uterine leiomyoma between 2009 and 2019 at a tertiary referral center in Turkey. The clinical characteristics of patients diagnosed with cellular leiomyoma (CL), leiomyoma with bizarre nuclei (LBN), mitotically active leiomyoma (MAL), and ordinary leiomyoma (OL) were examined. Disease recurrence and patterns of variants were evaluated.Results:Among the 1,581 women with uterine leiomyoma, the incidence of CL, LBN, and MAL were 2.9%, 1.2%, and 1.3%, respectively. The occurrence for a single mass (63% in CL, 78.9% in LBN, 61.9% in MAL, 38.8% in OL; p=0.001) was more common, and the diagnosis of intramural leiomyoma (67.4% in CL, 73.7% in LBN, 71.4% in MAL, 90.8% in OL; p=0.002) was less frequent in the leiomyoma variant groups compared with the OL group. Recurrent leiomyosarcoma was observed in one woman with MAL.Conclusions:This study showed that single mass rate was higher and intramural leiomyoma rate was lower in leiomyoma variants than in ordinary variants. Although rare, leiomyoma variants carry a risk of malignant recurrence after hysterectomy, suggesting the need for long-term follow-up.