18F-FDG PET/CT characterization and response evaluation in a case of lymphomatoid granulomatosis involving the main pulmonary artery.

ABSTRACT

Main pulmonary artery (MPA) involvement of lymphomatoid granulomatosis (LYG) is extremely rare. We described fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) findings in a case with LYG originated from the MPA. Fluorine-18-FDG PET/CT demonstrated nodular hypermetabolic foci in the MPA, corresponding well to the intraluminal filling defects on CT pulmonary angiography, and the secondary right heart dysfunction was observed. Final diagnosis was made after transcatheter MPA biopsies and multi-disciplinary consultation. The patient recovered completely following the steroid therapy and MPA stenting, which was illustrated on the second 18F-FDG PET/CT.