18F-FDG PET/CT manifestation of primary pulmonary mucosa-associated lymphoid tissue lymphoma

Abstract

Objective To analyze 18F-FDG PET/CT manifestation of primary pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma and improve the understanding and diagnosis of primary pulmonary MALT lymphoma. Methods The clinical data and 18F-FDG PET/CT data of 9 patients with primary pulmonary MALT lymphoma confirmed by pathology were retrospectively analyzed. Two senior PET/CT diagnostic physicians independently reviewed the films and recorded the location, number, density, size, morphology, and maximum standardized uptake value (SUVmax) of the lesions, as well as the mediastinal and hilar lymph nodes. Based on the data obtained, the image information was analyzed and related literatures were reviewed. Results Nine cases of primary pulmonary MALT lymphoma 18F-FDG PET/CT were divided into three types: consolidation shadows(n=4), solitary mass (n=3), and diffuse pneumonia (n=2). The type of consolidation shadows manifested as consolidation shadows with different size and involvement range. The type of mass manifested as single or multiple solid masses with rough edges, and the type of diffuse pneumonia manifested as diffuse plaques and clumps of soft tissue density shadows in the pulmonary lobe or both lungs. Signs of air bronchogram (n=8), signs of perfusion (n=3), calcification (n=2), pleural effusion(n=2) and mediastinal and hilar lymphadenopathy (n=2) were found in 9 patients. Lesions gathered at the center was seen in 4 patients. All lesions showed heterogeneous 18F-FDG uptake; the median SUVmax was 6.0 (2.6–8.3). Radioactive concentration of mediastinal and hilar lymphadenopathy was found in 2 cases of patients with diffuse pneumonia; SUVmax were 13.0, 4.7. Conclusion 18F-FDG PET/CT manifestation of primary pulmonary MALT lymphoma was solitary mass or consolidation shadows with signs of air bronchogram and heterogeneous 18F-FDG uptake. Combined with relatively slow progression, such manifestation can be considered primary pulmonary MALT lymphoma. Key words: Pulmonary; Mucosa-associated lymphoidtissue lymphoma; Positron emission tomography computed tomography; Fluorodeoxyglucose F18