ABSTRACT
Objective@#To explore the imaging presentation of 18F-FDG PET-CT and clinical characteristics of the patients with lymphoblastic lymphoma (LBL).@*Methods@#The clinical and imaging data of 18 patients with newly diagnosed LBL in the First Affiliated Hospital with Nanjing Medical University from July 2009 to June 2017 were retrospectively analyzed. The sensitivity, specificity and accuracy of 18F-FDG PET-CT to diagnose bone marrow involvement (BMI) was calculated respectively.@*Results@#There were 18 LBL patients, including 12 male and 6 female with median age of 24.5 (14-51) years old. Eleven patients were T-LBL, and 7 patients were B-LBL. All lesions were presented with high 18F-FDG uptake on 18F-FDG PET-CT imaging, with a median SUVmax of 14.3 (10.6, 16.8). The most frequent lymph node involvement site was mediastinal lymph nodes, and 7 T-LBL cases had jugular node involvement. The most frequent extranodal involvement site was bone marrow, with multifocal FDG accumulation in bone marrow on 18F-FDG PET-CT imaging in 8 cases. The median SUVmax of node and extranodal involvement were 15.0 (9.0, 18.2), 12.3 (8.4, 15.3), and there was no significant difference (Z=-0.867, P= 0.386). The median SUVmax of T-LBL and B-LBL patients was 14.1 (9.2, 15.9), 14.5 (12.1, 19.5) respectively, and there was no significant difference (Z=-0.679, P= 0.497). According to clinical features, 18F-FDG PET-CT and bone marrow biopsy (BMB), 12 patients were diagnosed as BMI. If multifocal FDG accumulation and diffuse hypermetabolism of FDG in bone marrow were considered as the diagnosis criteria, the sensitivity, specificity and accuracy of PET-CT was 91.7% (11/12), 66.7% (4/6), 83.3% (15/18), respectively. The parameters in BMB were 50.0% (6/12), 100.0% (6/6), 66.7% (12/18), respectively.@*Conclusions@#LBL mostly occurs in young men and its clinical manifestations include lymphadenectasis and invasion of bone marrow. 18F-FDG PET-CT has certain characteristics which are helpful to diagnose and staging.