Multinodular and Vacuolating Neuronal Tumor in the Brain Depth - Atypical Presentation of a New Tumor: A Case Report

Introduction: Multinodular and Vacuolating Neuronal Tumors (MVNTs) are clinically benign lesions and was recently included in the last World Health Organization Classification of Tumors of the Central Nervous System (WHO – 2016). Recent studies have discovered specific immunomarkers that classifies the MVNTs as a new neoplasm group placed within the section covering "Neuronal and mixed neuronal-glial tumors” as a WHO grade I lesion. Case report: We present a case of a probable MVNT in a 55-year old woman, who presented with chronic pattern seizures. Conventional MRI revealed an infiltrative and multinodular pattern lesion localized in the deep left cerebral hemisphere compromising the ventral posteromedial and pulvinar surfaces of thalamus, lateral geniculate body, choroidal fissure, mammillothalamic tract, fornix and septum pellucidum, anterior commissure, extending to contralateral globus pallidus and internal capsule. Dynamic susceptibility contrast-enhanced MR perfusion and Arterial Spin Labeling (ASL) technique didn’t show any abnormalities. MR spectroscopy demonstrated a mild increase in Choline (Cho) and mild reduction in N-acetyl aspartate (NAA). No substantial difference both clinically and radiologically was observed on five years follow up. Conclusion: The diagnosis of MVNT was made considering the extremally benign biological behavior of this tumor and the typical imaging features, despite of deep localization of the lesion, and once this kind of lesion was previously described as a “don’t touch lesion” the histological, biopsy was not performed.