Characteristic of Endometrial Stromal Sarcoma by Algorithm of Potential Biomarkers for Uterine Mesenchymal Tumor

The benign tumor uterine leiomyoma (UL) develops from the smooth muscle tissue that constitutes the uterus, whereas malignant tumor uterine sarcoma develops from either the smooth muscle tissue or stroma and is different from UL and endometrial cancer. Uterine sarcoma is broadly classified into three types: uterine leiomyosarcoma, endometrial stromal sarcoma (ESS), and carcinosarcoma. Although uterine leiomyosarcoma and ESS are both classified as uterine sarcoma, they significantly differ in terms of their sites of occurrence, symptoms, and treatment methods. Uterine leiomyosarcoma develops from the muscle tissue constituting the wall of the uterus and accounts for approximately 70% of all uterine sarcoma cases. In contrast, ESS develops from the stromal tissue beneath the endometrium and accounts for approximately 25% of all uterine sarcoma cases. ESS is classified as either low grade (LG) or high grade (HG). This case report aimed to highlight the importance of histopathologic examinations based on surgical specimens. Herein, we reported the case of a 45-year-old woman suspected of having submucosal leiomyoma of the uterus based on imaging results. Transvaginal ultrasonography and endometrial biopsy or partial dilation and curettage were performed. Contrast-enhanced magnetic resonance imaging (MRI) revealed a 32-mm mass projecting from the posterior wall of the uterus into the uterine cavity. T2-weighted imaging revealed a low signal within the mass; thus, submucosal UL was suspected. Histopathologic examination of surgical specimens obtained from a patient suspected of having submucosal UL after contrast-enhanced MRI indicated that the patient had ESS. Despite the remarkable advancements in medical imaging technology, the accuracy of contrast-enhanced MRI for detecting uterine mesenchymal tumors is limited. Therefore, histopathologic diagnosis based on surgical specimens should be performed when medical grounds for diagnosing a benign tumor on contrast-enhanced MRI are lacking.