Revisiting Imaging and Pathology of Malignant Appearing Uterine Smooth Muscle Tumors: A Mistaken Identity of Leiomyosarcoma on MRI

Uterine leiomyoma is a relatively common condition occurring in a majority of African American and Caucasian women by age 50. Magnetic resonance imaging of the pelvis with contrast is the modality of choice when evaluating uterine tumors. We report a case of a patient with a four-day history of intra-menstrual vaginal bleeding who underwent magnetic resonance imaging of the pelvis that suggested the tumor was a leiomyosarcoma, the malignant counterpart of leiomyoma. Therefore, the patient underwent pre-operative uterine artery embolization to decrease blood loss with exploratory laparotomy, resection of pelvic mass and dilation and curettage. Pathologic evaluation of the mass returned a diagnosis of leiomyoma. Magnetic resonance imaging evaluation of leiomyomata remains difficult. Further development of imaging parameters could improve diagnosis of benign uterine fibroids.