Importance of diagnostic methods for round ligament leiomyomas in clinical practice

Benign uterine leiomyoma (U.LMA) and malignant uterine leiomyosarcoma (U.LMS), which are both uterine mesenchymal tumors, are distinguished by the number of cells with mitotic activity. However, uterine mesenchymal tumors contain tumor cells with various cell morphologies; therefore, making a diagnosis, including differentiation between benign tumors and malignant tumors, is difficult. For example, round ligament leiomyomas are uterine leiomyomas with a very rare placental lobed tissue morphology that can be misdiagnosed as a malignant uterine leiomyosarcoma because of its rarity and characteristic appearance on gross examination. Similar to the detection of a suspicious malignant mass during magnetic resonance imaging (MRI) examination by medical staff, healthcare professionals must understand the characteristic appearance of round ligament leiomyomas. Clinicians and pathologists must understand the oncologic features of round ligament leiomyomas to prevent misdiagnosis of malignancy and consequent overtreatment.