Acute Brain Stroke Evolution Detected By F-18-Fdg Pet/Ct And Mri Justifies The Discordance Of Lesions In A Patient With Lymphoproliferative Syndrome

A 50-year-old man with angioimmunoblastic T-cell lymphoma in complete response to treatment presented new hypermetabolic brain lesions on 18F-FDG PET/CT suggestive of malignancy. These findings were correlated by MRI that showed cortical-subcortical peripheral lesions typical of acute ischemic infarction. A restaging 18F-FDG PET/CT showed that hypermetabolic lesions were replaced by ametabolic areas, supporting chronic infarction. Early ischemia presents transitory FDG increase. Brain lymphomas are highly FDG avid and difficult to differentiate from acute cerebral infarction. In view of the discordance of abnormal areas of intracranial uptake on PET FDG, MRI confirmation is required to avoid misinterpretation.