Spontaneous regression of a giant uterine leiomyoma after delivery: a case report and literature review

Abstract

Background: Uterine leiomyomas are hormone-dependent benign tumors and often begin to shrink after menopause due to the reduction in ovarian steroids. The influence of pregnancy on uterine leiomyomas size remains unclear. Here, we present a case of spontaneous regression of a giant uterine leiomyoma after delivery.

Case presentation: A 40-year-old woman presented with multiple uterine leiomyomas, one of which is a giant uterine leiomyomas (approximately 8 cm in diameter) that gradually shrinked after delivery. At over two months postpartum, the large myometrial leiomyoma had transformed into a submucosal leiomyoma, and over 3 years postpartum, both the submucosal leiomyoma and multiple intramural leiomyomas completely regressed.

Conclusion: Spontaneous regression of a giant uterine leiomyom is rare after delivery. Considering uterine leiomyoma regression until over 3 year postpartum,we need to observe the regression of uterine fibroid for a longer time postpartum in the absence of fibroid related complications. In addition, it will provide new insights for treatment options of uterine leiomyomas in the future.

Keywords: Postpartum; Pregnancy; Regression; Uterine leiomyomas.

Fig. 1

Ultrasound imgages from pre pregnancy to postpartum. (a) Ultrasound examination on December 14, 2018, showed multiple medium-to-low echogenicity (suggestive of leiomyomas) in the myometrium, with a larger one located in the posterior wall measuring approximately 3.5 × 4.0 × 2.7 cm (arrow). (b) Ultrasound examination on September 3, 2019, confirmed an early intrauterine pregnancy with an 8 mm embryo. Multiple medium-to-low echogenicity were observed in the myometrium, including a larger one in the posterior wall measuring approximately 5.5 × 3.5 cm (arrow), with a distinct boundary. (c) Ultrasound examination on April 30, 2020, 30 days postpartum, showed multiple heterogeneous hypoechoic masses in the uterine area. A large mass measuring 8.6 × 7.7 × 7.3 cm(arrow) was identified in the posterior wall. (d) Ultrasound examination on June 24, 2020 (> 2 months postpartum) showed an 8.6 × 3.6 cm hypoechoic mass (arrow) inside the uterine cavity with a distinct boundary. The hypoechoic mass inside the uterine cavity suggested a submucosal leiomyoma or a tissue residue. (e) Ultrasound examination on July 22, 2020, displayed a 6.5 × 3.4 cm hypoechoic mass (arrow) within the uterine cavity. (f) Ultrasound examination on April 19, 2021, indicated a 2.5 × 1.3 cm heterogeneous hypoechoic mass (arrow) within the uterine cavity. (g) Ultrasound examination on September 12, 2022, revealed a 1.0 × 1.0 cm hypoechoic mass (arrow) near the endometrium of the posterior wall of the uterine body. (h) Ultrasound examination on May 8, 2023, revealed no hypoechoic changes in the posterior wall (arrow)