Transient Uterine Myometrial Contraction Associated with Moles

Purpose: To examine the incidence of transient distortion of uterine central tissue and myometrial hypointense areas observed on MR images in women with clinically suspicious moles. Materials and Methods: The study population consisted of six women aged 15-47 years with clinically suspicious moles (hydatidiform mole in four, invasive mole in one, and microscopic mole in one). The control study population was 105 reproductive-age women (18-52 years) without uterine malignancy, gestational trophoblastic disease, or pregnancy. MR images were analyzed to check for discrepancies of the uterine central tissue configuration. If a discrepancy was observed, the myometrial hypointense area, its diameter, and changes in its shape and location were analyzed. Results: Differences in uterine central tissue configuration and hypointense areas were observed in all six patients. In the control study, only seven cases showed uterine endometrial distortion, and five exhibited hypointense areas. These areas disappeared, changed in shape, or other hypointense areas appeared on subsequent MR images. Significant differences (P < 0.01) in the incidence of uterine central tissue distortion and hypointense areas, and in their maximum diameter between the study and the control groups were observed. Conclusion: Uterine myometrial hypointense areas with central tissue distortion, most likely due to transient myometrial contraction, are frequently seen in women with clinically suspicious moles.