Neurosarcoidosis presenting with simple partial seizures and solitary enhancing mass: case reports and review of the literature

A 37-year old woman, who had presented 5 years earlier with suspected simple partial seizures, returned with seizures increasing in frequency and intensity, confirmed by video/electroencephalography (VEEG) monitoring with left frontotemporal onset. A low-grade tumor was suspected, given a magnetic resonance imaging (MRI) study demonstrating enlargement of the left amygdala, anterior hippocampus, and adjacent mesial temporal neocortex, with modest gadolinium enhancement, and a positron emission tomography (PET) scan showing increased metabolism within that region. Surgical resection of the left mesial temporal lobe was performed and pathology revealed pathogen-free granulomas. She was given a diagnosis of sarcoidosis (following chest computed tomography that showed hilar adenopathy). She was treated with oral steroids for neurosarcoidosis with no further epileptic seizures in 19 months of follow-up. The second case was a young man, with known pulmonary sarcoidosis, who developed simple partial seizures and, later, complex partial seizures, with MRI revealing a left insular mass. Stereotactic biopsy again demonstrated pathogen-free granulomas. He has also done well in 4 years of follow-up. Review of the literature suggests that seizures associated with sarcoidosis do not invariably imply a poor prognosis. Certain features-multifocal parenchymal involvement, hydrocephalus, and chronic meningitis-were associated with poor outcome. In contrast, cases with isolated mass lesions often fared well.