The imaging pattern of lung involvement in malignant lymphoma by PET/CT

Objective: The value and imaging pattern of 18F-fluorodeoxyglucose (FDG) PET/CT in specific evaluation of lung involvement in patients with malignant tymphoma (ML) have not been well documented in the current literature. The purpose of this study was to perform pattern analysis and to highlight the advantages of FDG PET/CT in such patients. Methods: The FDG PET/CT results of 78 malignant lymphoma cases with lung involvement were retrospectively investigated. These included 47 eases of non-Hodgkin's lymphoma (NHL), 10 cases of Hodgkin's lymphoma (HL) and 21 cases of unclassified lymphoma. Thirty-one lymphoma cases were confirmed after having undergone FDG PET/CT for initially uncertain clinical diagnosis. Forty-seven cases with known lymphoma underwent FDG PET/CT for staging, re-staging and monitoring. Results: Six imaging patterns on FDG PET/CT were classified in 78 cases of malignant lymphoma with lung involvement: (1) nodular or mass-like pattern (46/78); (2) fibrous or patchy intiltrative pattern (29/78); (3) pleural and pericardia[ involvement (23/78); (4) bilateral diffuse parenchymal lung disease (12/78); (5) segmental or lobar pulmonary atelectasis (9/78); (6) circumscribing hilar lymphadenopathy (7/78). More than 1 pattern could coexist in a patient. Besides lymph nodes and lung involvement, other organs of lymphoma disease included: bone marrow and cortex, stomach, subcutaneously soft tissue, mammary gland, kidney, liver and laryngopharynx. Conclusions: Whole-body FDC PET/CT is useful for evaluation of lymphoma disease with specific lung involvement. By analyzing the different types of imaging pattern, it may hopefully add to the details of staging, re-staging and treatment monitoring of this disease entity. (authors)