Isolated neurosarcoidosis presenting similarity to malignant meningioma on neuroimaging findings

Abstract

We report a case of isolated neurosarcoidosis mimicking malignant meningioma. A 75‒year‒old woman presented to our hospital due to right hemiparesis, aphasia, and impaired mental activity. Magnetic resonance imaging (MRI) revealed an intradural enhanced tumor attaching from the left convexity to the falx cerebri with coexisting peripheral edema in left frontoparietal white matter. Positron emission tomog-raphy (PET) using18F‒fluorodeoxy glucose,11C‒methionine, and11C‒choline tracers showed high uptake in the enhanced lesion on MRI. Magnetic resonance spectroscopy (MRS) of the lesion revealed elevated choline and lactate peaks. Based on these neuroimaging findings, malignant meningioma was suspected, and the patient underwent subtotal surgical resection via frontotemporal craniotomy. The pathological diagnosis was isolated neurosarcoidosis, which can present similar neuroimaging findings on MRI, PET, and MRS to malignant meningioma. In cases of intracranial tumors, isolated neurosarcoidosis mimicking malignant meningioma should be considered preoperatively as a differential diagnosis to allow for appropriate treatment planning.