A 62-year-old man, previously treated for oral cavity carcinoma, presented with new-onset cognitive-motor symptoms. Brain MRI revealed a periventricular, avidly enhancing lesion in the right anterior basal ganglia and hypothalamus suspicious for a brain tumor, particularly CNS lymphoma. 18 F-FDG brain PET/CT showed corresponding uptake suggestive of primary brain tumor, lymphoma, or metastasis. Follow-up MRI showed resolution of enhancement and mass effect favoring an evolving subacute infarct. The diagnosis of an infarct in the recurrent artery of Heubner territory was facilitated by MRI, and recurrent artery of Heubner infarction was noted as a potential cause for false-positive 18 F-FDG uptake on PET/CT, mimicking intracranial tumor.