Pulmonary mucosa-associated lymphoid tissue lymphoma: 18 F-FDG PET/CT and CT findings in 28 patients.

OBJECTIVE: The aim of the study was to evaluate the CT and fluorine-18-fluorodeoxyglucose positron emission tomography/CT (18 F-FDG PET/CT) imaging findings of lung mucosa associated lymphoid tissue (MALT) lymphoma.

METHODS: 28 patients with histologically confirmed pulmonary MALT lymphoma who underwent a chest CT and 18 F-FDG PET/CT for staging were retrospectively analysed. The CT images were evaluated to determine morphological pattern of appearance, laterality, localization, number, size, presence of thoracic lymphadenopaties and secondary/combined findings. PET images were analysed visually and semi-quantitatively by measuring the maximum standardized uptake value (SUVmax), lesion-to-liver SUVmax ratio and lesion-to-blood pool SUVmax ratio. The relationship between qualitative and semi-quantitative features at 18 F-FDG PET/CT and CT findings were also analysed.

RESULTS: A total of 57 pulmonary lesions were identified by CT: 37 areas of consolidation, 4 masses, 12 nodules and 4 ground-glass opacities. Solitary and multiple lesions were detected in 10 and 18 patients, respectively; among patients with multiple lesions, 16 were bilateral and 2 unilateral. 18 F-FDG PET/CT revealed increased 18 F-FDG uptake in 47/57 lesions, in 26/28 patients. 18F-FDG avidity was significantly associated only with tumour size.

CONCLUSIONS: Pulmonary MALT lymphoma is 18 F-FDG avid in most cases and 18 F-FDG avidity is correlated with tumour size. Consolidation is the most frequent morphological pattern of disease presentation. Advances in knowledge: This study demonstrated that lung MALT lymphoma are 18 F-FDG avid in most cases depending on tumour size. Single or multiple areas of consolidation are the most common pattern of presentation of lung MALT lymphoma at CT.