NIMG-94. A RARE CASE OF INFRATENTORIAL CEREBELLAR VERMIS MULTINODULAR AND VACUOLATING NEURONAL TUMOR

Abstract

Abstract INTRODUCTION Multinodular and vacuolating neuronal tumor (MVNT) is a rare entity that was first recognized by the World Health Organization Classification of Tumors of the Central Nervous System in 2016. The majority of MVNT cases reported were supratentorial in location and only a small subset of cases included infratentorial involvement. In the supratentorial, MVNT is often a nidus for seizure and surgical resection is for seizure control. Infratentorial MVNT lesions are typically not or only mildly symptomatic; thus, surgical intervention may not be warranted. Here we describe the clinical course of a patient who was found to have a cerebellar vermis lesion that consistent with infratentorial MVNT. CASE REPORT A 41-year-old man sought care due to new onset headache. A brain magnetic resonance imaging (MRI) exam revealed a coalescence of bubble-like cystic lesions in the cerebellar vermis that were T1 hypointense, T2/Flair hyperintense without contrast enhancement. Initially, the lesions were attributed to neurocysticercosis but work-up was not supporting the diagnosis. MRA of head and neck found no cerebral stenosis or vascular malformation. The unique MRI features support infratentorial MVNT diagnosis. Disease course, work-up and MRI features are not consistent with low grade glioma, subacute ischemia infarct, demyelinating disease or chronic fungal or parasite infection. Brain MRI surveillance has completed every 6 months; no interval change to the cerebellar vermis lesions has been seen over past two years. Clinically, the patient has been doing well and his headache has resolved. DISCUSSION MRI features of MVNT are predominantly mixed solid and cystic, bubble-like, T2/Flair-hyperintense, T1 hypointense lesions in the deep cortical region and superficial white matter without contrast enhancement. This case demonstrates that although no specific criteria to diagnose MVNT, neurologists and neuro-oncologists should be aware of the distinguishing radiographic features, which can help patients avoid unnecessary testing and potentially harmful interventions.