F-18 FDG PET/CT findings in two patients with pyothorax-associated lymphoma

We report 2 cases of pyothorax-associated lymphoma that underwent F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) examinations during pre- and post-treatment states. The FDG PET/CT examinations were able to define the massive lesions as areas of intensive FDG uptake. After radiotherapy, follow-up PET/CT examinations showed the disappearance of the abnormal FDG uptake, although the residual masses remained in the original regions. Finally, we concluded that these lesions had entered remission based on the PET/CT findings. These cases indicate that PET/CT is a useful modality for detecting pyothorax-associated lymphoma and for evaluating the efficacy of treatments.