Figure 8c. Extranodal disease in a 33-year-old man with a history of aggressive non-Hodgkin lymphoma who had undergone chemotherapy 1 year earlier. Axial PET scan (b) demonstrates intense FDG uptake in the posterosuperior oral cavity (arrows). (a, c) Axial CT (a) and PET-CT fusion (c) images demonstrate that the uptake (arrows) corresponds to the palatine tonsils, with minimal asymmetry seen at CT. In the tonsillar lymphatic tissues, physiologic uptake cannot be differentiated from extranodal lymphoma, especially in cases of subtle CT findings.