We present a 45-year-old man with newly generalized tonic-clonic seizures due to a contrast-enhancing frontal lesion with perifocal edema suggestive for high-grade glioma (HGG). For further evaluation, a dynamic 18F-FET PET scan was performed, which showed high 18F-FET-uptake with early peak and constantly decreasing time-activity curves, a characteristic feature of HGG. Stereotactic biopsy and histological evaluation excluded a neoplastic lesion but confirmed a manifestation of neurosarcoidosis with strong expression of the L-amino-acid-transporter considered responsible for 18F-FET-uptake. Therefore, unknown manifestations of neurosarcoidosis represent a clinical pitfall in 18F-FET PET and can mimic HGG.
From the *Department of Nuclear Medicine, University Hospital, LMU Munich;
†German Cancer Consortium (DKTK), partner site Munich, Munich;
‡German Cancer Research Center (DKFZ), Heidelberg; and
§Department of Neuropathology,
∥Institute of Clinical Neuroimmunology, and
¶Department of Neurosurgery, University Hospital, LMU Munich, Munich, Germany.
Received for publication June 18, 2018; revision accepted July 20, 2018.
Conflicts of interest and sources of funding: none declared.
Correspondence to: Marcus Unterrainer, MD, MSc, Department of Nuclear Medicine University Hostpital, LMU Munich Marchioninistr. 15, 81377 Munich, Germany. E-mail: firstname.lastname@example.org.