Background: Uterine leiomyomas appear after menarche, typically grow during the reproductive years, and then stabilize or regress after menopause. However, there have been several reports of a considerable number of patients who have undergone surgery for uterine leiomyomas during the postmenopausal period. In this paper, we discuss two issues: the possible reasons for the growth of uterine leiomyomas and the differential diagnoses of presumed leiomyomas in postmenopausal women. Methods: PubMed was searched for studies about uterine leiomyomas and sarcomas with a focus on postmenopausal women. Main findings: Several hypotheses exist for the growth of postmenopausal leiomyomas. Among these, we propose the following as an important candidate: estrogen and progesterone do not necessarily work in a positive way. In addition, in postmenopausal patients, the incidence of malignant tumors is very high, and it is generally difficult to diagnose uterine sarcoma prior to surgery. Conclusion: We propose that in cases in which uterine sarcomas cannot be ruled out, physicians should proactively consider surgery, particularly for postmenopausal patients.
