Cerebritis is a local or diffuse inflammatory reaction within the brain, usually secondary to various local or systemic etiologies. We are reporting a challenging case of a focal brain lesion mimicking neoplasm that presented with a seizure caused by idiopathic focal cerebritis. A 35-year-old male presented with three episodes of generalized tonic clonic seizures. Neurological exam was nonfocal. Cerebrospinal Fluid (CSF) showed 30 WBC with 75% lymphocytes. CSF studies including Bacterial culture, fungal culture and CMV/VZV/EBV/HSV PCR’s, were negative. EEG was unremarkable.CT brain showed round cortical thickening in right posterior parietal lobe. Brain MRI revealed a non enhancing right posterior parietal lesion. Magnetic Resonance Spectroscopy (MRS) showed increased choline activity with mildly increased N-acetylaspartate (NAA) and a lactate peak, suspicious for low grade glioma. Whole body imaging ruled out malignancy. Other infectious and inflammatory workup including urine and blood cultures, serum antibodies for HIV/syphilis/Hepatitis A, B, ESR, CRP and ANA were unremarkable. The lesion was surgically resected. The biopsy revealed inflammatory changes with predominantly perivascular (without arterial involvement) and diffuse parenchymal involvement. The inflammatory infiltrate was mainly mononuclear but was not granulomatous. Demyelination was not evident. Special staining ruled out the presence of mycobacteria, fungi, spirochetes and parasites. Immunohistochemical stains revealed the polyclonal (non-neoplastic) nature of the lymphoid and plasmacytic infiltrates, and negative viral antigens; HSVI & II, EBV, SV 40 and viral inclusions were not observed. The patient has been seizure free after levetiracetam treatment at 1-month followup. Although uncommon, a neoplasm-like mass lesion on MRI can actually be a focal cerebritis, which more rarely can be idiopathic. A full investigation in respect to the nature of such lesion is of paramount importance for the decisions related to treatment and prognosis.
Citation: Ezzeldin E, Yassin A, Graf D, Campbell G, Moghimi N, et al. 2019. Idiopathic Focal Cerebritis Mimicking a Neoplasm.J Neurol Exp Neurosci 5(2): 106-109.