Beyond Parkinsonism: 18 F-FDOPA Brain PET/MRI for Detection of High-grade Glioma.

A 72-year-old man presented with right-sided rigidity and bradykinesia, but the history and neurological examination were not entirely compatible with degenerative parkinsonism. Initial MRI showed T2/FLAIR hyperintensity within the splenium, attributed to small vessel disease. Subsequent 18 F-FDOPA brain PET/MRI ruled out degenerative parkinsonism, but revealed avid tracer uptake (SUVmax 4.46) in the splenium corresponding to signal abnormality on structural imaging. This unexpected finding prompted contrast-enhanced MRI brain, which identified a peripherally enhancing splenium lesion concerning for neoplasm. Stereotactic biopsy confirmed GFAP-positive, diffuse high-grade glioblastoma, IDH-wildtype, WHO Grade 4, highlighting the role of FDOPA PET in the assessment of primary brain tumors.