Unexpected finding of cerebral meningioma on (11)C-PiB PET

Area of Science:

• Neuroimaging
• Neuropathology
• Oncology

Background:

• Amyloid imaging using Carbon-11 Pittsburgh Compound B (C-PiB) PET is primarily used for detecting amyloid plaques in Alzheimer's disease.
• Meningiomas are typically benign tumors arising from the meninges, usually diagnosed via MRI or CT scans.

Observation:

• A 69-year-old healthy male volunteer in an amyloid imaging study unexpectedly exhibited increased C-PiB uptake in the left frontal region on PET scans.
• Subsequent Magnetic Resonance Imaging (MRI) revealed an extra-axial left frontal mass with mild enhancement, consistent with a meningioma.

Findings:

• The C-PiB PET scan revealed focal, increased binding in an area corresponding to the meningioma.
• This case suggests that meningiomas may exhibit abnormal binding of C-PiB, a tracer typically associated with amyloid plaques.

Implications:

• This incidental finding suggests C-PiB PET may have a role in identifying meningiomas, even in individuals without cognitive impairment.
• Further research is warranted to understand the mechanism of C-PiB binding in meningiomas and its diagnostic utility.
• This case broadens the differential diagnosis for focal C-PiB uptake beyond neurodegenerative diseases.