FET PET in Primary Central Nervous System Vasculitis.

Area of Science:

• Neurology
• Neuroimaging
• Pathology

Background:

• Primary central nervous system vasculitis (PCNSV) affects the brain and spinal cord.
• Inflammatory markers are often normal in PCNSV, complicating diagnosis.
• Conventional angiography can aid diagnosis, but brain biopsy is definitive.

Observation:

• A 57-year-old man presented with a new-onset generalized epileptic seizure.
• Magnetic resonance imaging (MRI) showed a contrast-enhancing lesion.
• Positron emission tomography (PET) with O-(2-[F]fluoroethyl)-L-tyrosine revealed increased metabolic activity.

Findings:

• These imaging findings were highly suggestive of a malignant glioma.
• Histological examination of a stereotactic biopsy unexpectedly revealed small-vessel vasculitis.

Implications:

• This case highlights the importance of considering PCNSV in the differential diagnosis of enhancing brain lesions.
• Central nervous system biopsy remains the gold standard for diagnosing PCNSV, even when initial imaging suggests malignancy.
• Accurate diagnosis is critical for appropriate treatment and patient management.