Diagnostic value of contrast-enhanced ultrasonography in mediastinal leiomyosarcoma mimicking aortic hematoma: A case report and review of literature

BACKGROUND: Primary mediastinal leiomyosarcomas are extremely rare. We report a case of leiomyosarcoma around the thoracic and abdominal aorta, mimicking an aortic hematoma, and discuss the diagnostic value of ultrasound. CASE SUMMARY: A 63-year-old female was hospitalized for abdominal pain. Initial computed tomography angiography revealed an enhanced mass around the lower thoracic and upper abdominal aorta. Aortic hematoma was strongly suspected, and stents were placed by interventional surgery. About 1 mo postoperatively, the patient was re-hospitalized because of progressive abdominal pain. Ultrasound showed that the mass had a heterogeneous echo. In contrast-enhanced ultrasound, the hyperechoic regions were filled with contrast medium after the aortic region was, indicating that the blood supply was abundant but had no direct connection with the aorta. There was no obvious contrast medium-filling in the hypoechoic area. These findings were similar to those of malignant tumors with liquefaction and necrosis. Positron emission tomography/computed tomography confirmed that the mass had a high metabolic signal similar to that of a malignant tumor. Leiomyosarcoma was confirmed by postoperative pathology. CONCLUSION: Symptoms of mediastinal leiomyosarcoma surrounding the aorta may mimic aortic hematoma. Contrast-enhanced ultrasound can provide valuable and unique diagnostic clues.