FDG-PET in diagnostic work-up of pulmonary artery sarcomas

Abstract

To the Editors: Pulmonary artery sarcomas (PAS) represent a group of rare tumours with a poor prognosis. In a recent review, the mean±sd survival of patients with this disease was 11±3 months when no curative resection was attempted, whereas patients undergoing curative resection had a survival of 36.5±20.2 months 1. Appropriate application and interpretation of different imaging modalities facilitates differentiation of PAS from chronic thromboembolism. Findings in chest computed tomography (CT) could be inhomogeneous attenuation, vascular distension or filling defects of the entire luminal diameter of a proximal or main pulmonary artery 2, 3. Extraluminal extension of the tumour can be a specific finding of PAS. Magnetic resonance imaging (MRI) aids the determination of the extent of masses and the relationship to adjacent structures, and during postoperative follow-up 4. The degree of contrast enhancement in MRI was shown to correlate with the degree of tumour differentiation, and contrast enhancement might be used to differentiate neoplasm from central pulmonary embolism 5. Single case reports have shown that fluorodeoxyglucose-positron emission tomography (FDG-PET) might be helpful in differentiating PAS from pulmonary thromboembolic disease, and helps decision-making when it is not possible to perform intraoperative biopsies for histological confirmation of PAS before attempting curative pneumonectomy 6, 7. In the current study, we present three cases of patients with PAS, in whom a presumptive diagnosis of PAS was made preoperatively based on clinical, CT and MRI findings and a positive FDG-PET scan. Case 1 was a 48-yr-old male nonsmoker with absence of previous medical history who presented with progressive dyspnoea. On spiral contrast-enhanced CT scan taken 4 months prior to presentation, a left-sided paracentral pulmonary embolism was suspected. No …