A Rare Case of Benign Metastasizing Leiomyoma Causing T11 Spinal Cord Compression: A Report and Literature Review

Diagnosis of uterine smooth muscle tumors depends upon histologic characteristics as both benign and malignant share clinical features such as metastases. A benign metastasizing leiomyoma is a rare benign smooth muscle tumor that metastasizes to extrauterine sites with simultaneous uterine leiomyoma or previously biopsy-proven leiomyoma during myomectomy or hysterectomy. Benign metastasizing leiomyoma metastasizes outside the uterus, predominantly to the lungs and lymph nodes. However, the involvement of other organs, such as the heart, liver, spine, and soft tissue, is also reported. Here, we present a case of a 42-year-old woman with a history of uterine leiomyoma with prior myomectomy and hysterectomy, who presented with worsening back pain and lower extremity weakness and was found to have an acute cord compression, a serious complication caused by mass effect and a medical emergency that requires prompt attention to prevent permanent spinal cord damage. Sacral soft tissue biopsy and T11 spinal bone biopsy both demonstrated leiomyoma with immunostains positive for desmin, smooth muscle actin, and positive estrogen and progesterone receptors. No atypia, necrosis, and mitosis were identified. The patient had hepatic and pulmonary metastasis on imaging. The final diagnosis was benign metastasizing leiomyoma. There is no standard treatment for benign metastasizing leiomyoma. Both surgical and pharmacological approaches are employed. Although most cases are benign, there is a possibility for life-threatening complications. Benign metastasizing leiomyomas can be considered when multiple soft tissue tumors are found in premenopausal women with a history of uterine leiomyomas. Multidisciplinary discussion between oncologists, gynecologists, and relevant specialists is crucial in the optimal evaluation and treatment of benign metastasizing leiomyoma.