[Differential diagnosis between pulmonary artery sarcoma and central chronic pulmonary thromboembolism:a preliminary study on CT signs].

ABSTRACT

Objective: To improve the diagnostic accuracy of pulmonary artery sarcoma, and to distinguish it from central chronic pulmonary thromboembolism using CT scans. Methods: In this retrospective study, two groups of pulmonary artery sarcoma (PAS group) and central chronic pulmonary thromboembolism (central CPTE group) confirmed by pathology at our hospital between August 2009 and July 2019 were enrolled, clinical features and pre-operative CT pulmonary artery manifestation were collected, and the key points of differential diagnosis were summarized. Results: The study was composed of 13 cases in the PAS group including 10 males (76.9%), with an average age of (45.4±15.5) years. There were 19 patients in the central CPTE group including 14 males (73.7%), with an average age of (38.6±14.1) years. There were no significant differences in gender and age between the two groups. Deep venous thrombosis in the lower extremities was significantly higher in the central CPTE group than in the PAS group (7/19 vs. 0/13, P=0.025), and the N-terminal pro-brain natriuretic peptide value was higher in the central CPTE group than in the PAS group [674.50(261.70-1 977.70) vs. 66.00(28.10-505.50),P=0.001]. In CT pulmonary angiography, the involvement of the main pulmonary artery, and the proximal lesion showing an acute angle to the pulmonary artery wall were more common in the PAS group [11(84.6%) vs. 5(26.3%), P=0.003; 11(84.6%) vs. 2(10.5%), P<0.001, respectively]. The swelling index of the main pulmonary and the left/right main pulmonary arteries in the PAS group were significantly higher, as well as the dilatation in the lobar and segmental pulmonary arteries [1.19±0.17 vs. 0.99±0.19,P=0.006, 10(76.9%) vs. 2(10.5%), P<0.001, respectively]. The right ventricular transverse diameter/left ventricular transverse diameter (RVd/LVd) and pulmonary artery diameter/ascending aortic diameter ratio (Pad/Aod) were significantly lower in PAS group than those in the central CPTE group (0.97±0.19 vs. 1.23±0.35,P=0.020; 0.98±0.25 vs. 1.15±0.20,P=0.039). Conclusions: In CT pulmonary angiography, filling defects involving the main pulmonary artery and showing expansive growth were highly suggestive of pulmonary artery sarcoma. The history of deep venous thrombosis of the lower extremities was helpful for the diagnosis of chronic pulmonary embolism.