Primary Benign Intraosseous Meningioma on 18F-FDG PET/CT Mimicking Malignancy

We present a case of primary benign intraosseous meningioma in the sphenoid bone mimicking malignancy. A 44-year-old female patient who had a protruding right eye and headache came to our hospital. MRI showed a large, destructive, heterogeneously well-enhancing soft tissue mass in the right sphenoid bone suggesting malignancy. 18F-FDG PET/CT showed a hypermetabolic mass in the same site with an SUVmax of 9.1 The pathological diagnosis by surgery revealed that this tumor was a WHO grade I transitional meningioma. This case suggests that primary benign intraosseous meningioma may show high 18F-FDG uptake mimicking a malignancy.