Primary pulmonary artery sarcoma with intrapulmonary metastases based on PET/CT imaging: a case report and literature review

Primary pulmonary artery sarcoma is an extremely rare and highly aggressive malignant tumor of cardiovascular system. It is usually misdiagnosed as pulmonary thromboembolism due to its atypical clinical features and similar clinical symptoms. Different from published reports, our case received both enhanced CT and 18F-FDG PET/CT examination before the pathologic result, and lung metastases had already occurred at the time of diagnosis. We herein reported a case of 41-year-old female patient who suffered from cough and chest tightness for more than a month. Laboratory examination indicated that both blood routine and tumor markers were within the normal range, and only the D-dimer slightly elevated. Contrast-enhanced chest computed tomography showed right pulmonary artery lesion and multiple nodular located right upper lung, the lesion was mild heterogeneous enhancement. No obvious abnormalities were found in deep vein of bilateral lower extremities on ultrasonography. In order to confirm the nature of these lesions, PET/CT scan was performed, which revealed stripe hypermetabolism in right pulmonary artery and nodular hypermetabolism in right upper lung, and the rest of the whole-body PET imaging were negative, a diagnosis of primary pulmonary artery malignancy with pulmonary metastases was made, and pulmonary thromboembolism was ruled out. Biopsy of right pulmonary lesions was performed and histopathological examination indicated pulmonary artery sarcoma. She only received palliative conservative medical treatment because the disease was late stage according to the tumor-node-metastasis (TNM) staging system, and did not acceptable surgical treatment, and was in good health during recent follow-up. Our study suggested that 18F-FDG PET/CT image is a good approach for the diagnosis of pulmonary artery sarcoma and could provide adjunct value for further treatment.