Undifferentiated intimal sarcoma of the pulmonary artery: A case report

BACKGROUND: Since 1923, only a few hundred cases of pulmonary arterial sarcoma (PAS) have been reported. It is easy for PAS to be misdiagnosed as pulmonary thromboembolism, which makes treatment difficult. The median survival time without surgical treatment for PAS is only 1.5-3 mo. Echocardiography is widely used in screening for pulmonary artery space-occupying lesions in patients with chest pain, dyspnea, and cough; furthermore, it is typically considered the first imaging examination for patients with PAS. CASE SUMMARY: In May 2017, a 39-year-old male patient experienced chest pain with no particular obvious cause. At that time, the cause was thought to be pulmonary embolism. In July 2017, positron emission tomography–computed tomography revealed space-occupying lesions in the right lung and multiple metastases in both lungs. The lesions of the right lung were biopsied, and pathology revealed undifferentiated sarcoma. Chemotherapy had been performed since July 2017 in another hospital. In December 2019, the patient was admitted to our hospital for the sake of CyberKnife treatment. Echocardiography suggested: (1) A right ventricular outflow tract (RVOT) solid mass of the main pulmonary artery; and (2) mild pulmonary valve regurgitation. Ultrasonography showed the absence of a thrombus in the deep veins of either lower limb. CONCLUSION: PAS is a single, central space-occupying lesion involving the RVOT and pulmonary valve. Echocardiography of PAS has its own characteristics.