Ovarian myxoid leiomyosarcoma on PET/CT and enhanced CT: A case report and literature review

Primary leiomyosarcoma of the ovary is extremely rare, accounting for only 1% of ovarian tumors. Myxoid leiomyosarcoma (MLMS) is one of the subtypes. As far as we know, only few cases have been reported, and there is no imaging report of ovarian MLMS. This paper reports a case of primary MLMS of the ovary with multiple complex predominantly cystic masses and mild metabolism on PET/CT, and reviews the literature. A 70-year-old woman was admitted to the hospital due to intermittent abdominal distension accompanied by edema of lower limbs for 3 months. Abdominal CT showed multiple irregular complex predominantly cystic masses in the abdominal and pelvic cavity, with unclear lesion boundaries, and patchy mild to moderate enhancement. PET/CT showed inhomogeneous low uptake of FDG, SUV_max: 2.2；In the cystic area, there are multiple flocculent flotations with no FDG uptake. The patient underwent tumor debulking and omentectomy. Intraoperative exploration revealed that the tumors were complex, predominantly cystic masses accompanied by multiple solid septa, which originated in the right ovary. Finally, ovarian MLMS was histologically confirmed. Due to extensive myxoid degeneration, MLMS of the ovary is mostly manifested as large complex predominantly cystic masses on imaging, with uneven and mild uptake of glucose. In this paper, enhanced CT and FDG PET/CT findings of ovarian MLMS were reported, which made up the gap in the imaging of this disease.