Multifocal Meningiomas Mimicking Dural-Based Intracranial Metastases at 18F-Fluciclovine PET/CT.

A 78-year-old man with biochemically recurrent prostate adenocarcinoma (prostate-specific antigen, 2.3 ng/mL) but without detectable disease in the chest, abdomen, or pelvis at conventional CT imaging or in the bones at Tc-MDP scintigraphy underwent F-fluciclovine (anti-1-amino-3-F-fluorocyclobutane-1-carboxylic acid) PET/CT to evaluate for occult recurrent or metastatic disease. Imaging identified intense radiotracer uptake within 3 dural-based lesions along the left cerebral convexity. Subsequent MRI and biopsy confirmed multifocal World Health Organization grade 2 atypical meningiomas. Focal intracranial radiotracer uptake at F-fluciclovine PET/CT may create a diagnostic dilemma as incidental meningiomas can mimic intracranial metastases.