Extranodal lymphoma, secondary to or accompanying nodal disease is uncommon, but not unusual finding. 18-Fluorodeoxyglucose positron emission tomography (18F-FDG PET/CT) imaging has an essential role in the staging of lymphoma, in treatment response monitoring, and in detection of recurrence. We present a case of a 52-year-old man with generalized diffuse large B-cell lymphoma (DLBCL) with multiple extranodal sites involvement detected by 18F-FDG PET/CT. With this clinical case we demonstrate that 18F-FDG PET-CT is a more effective technique than CE-CT for the evaluation of viable extranodal involvement of the diffuse large B-cell lymphoma (DLBCL) and should be combined in the monitoring of DLBCL