Pulmonary Artery Sarcoma Masquerading as Pulmonary Embolism and Infection: a Case Report

A 61-year-old man with hypertension had developed exertional dyspnea for 2 years. His symptom got worse with fever and wet cough 4months prior to admission (PTA), and inspiratory pain on his right chest 3 months PTA. He was suspected of having an atypical pneumonia or a tuberculosis on CT. Enhanced chest CT showed large mural defects in right main pulmonary artery, clearly delineated by contrast medium.He was diagnosed as having a pulmonary embolism and received anticoagulation therapy with heparin followed by warfarin. Despite 1 week of warfarin therapy, he remained symptomatic with no change in the pulmonary artery filling defects on repeated enhanced CT.Pulmonary artery sarcoma, or a metastatic tumor were suspected of by its time course and accompanying symptoms and signs of fever, secondary anemia, and weight loss. Increased uptake of FDG in the affected pulmonary artery indicated that pulmonary artery sarcoma was most likely.Aspiration cytology and needle biopsy through pulmonary artery catheter revealed malignant cells with results of CD31(-), CD34(-), D2-40(+),α-Actin(-), and AE1/AE3(+), consistent with pulmonary artery sarcoma which was not able to be specified further.It was out of operative indication because of distant metastasis in his lungs. Therefore, he received weekly Paclitaxel(45mg/m2) + Carboplatin(AUC 2)concurrent with TRT 60Gy/30Fr in order to mainly control intra-arterial mass. However, we discontinued it at 6courses because of neutropenia(Gr3) and development and progression of non-tuberculosis mycobacterium infection. He was also intolerable to pazopanib due to many side effects of increasing in the liver enzymes(Gr1), hypertension(Gr3), anorexia(Gr3), diarrhea(Gr3), nausea(Gr3) and NTM exacerbation. On the other hand, his primary and metastatic lesions have a tendency to decrease in size in comparison with one before chemotherapy. We will report this case with literature review in terms of diagnostic difficulty of pulmonary artery sarcoma.