Advanced multiparametric MRI and FDG-PET/CT in multinodular and vacuolating neuronal tumor: A pathologically confirmed case.

Multinodular and vacuolating neuronal tumor (MVNT) is a relatively new disease concept proposed in 2013 and was classified as a separate tumor type in 2021 by the World Health Organization (WHO) classification. MVNT can cause seizures but is a benign disease, with no cases of enlargement or postoperative recurrence reported. Recent reports described advanced MRI features in MVNT cases, but the diagnosis of MVNT is usually based on characteristic MRI findings of clusters of nodules. Here, we report advanced multiparametric MRI and FDG-PET/CT findings in a case of MVNT with epileptiform symptoms that was pathologically confirmed by surgery.

New Imaging Features of Multinodular and Vacuolating Neuronal Tumor Revealed by Alcohol and Illicit Drugs Consumption.

It has been almost a decade since the multinodular and vacuolating neuronal tumor (MVNT) was first described. In 2021, WHO classified it as a defined entity, and it is considered one of the glioneuronal and neuronal tumors. Due to its similarities with dysembryoplastic neuroepithelial tumors (DNET), some authors consider it a variant of these, ranking in the category of malformations, but genetic alterations favor a neoplastic origin. We present a 29-year-old male with a generalized onset tonic-clonic seizure after a nightclub party. Imaging studies revealed a right temporal multinodular and vacuolating neuronal tumor confirmed by biopsy. It is considered a nonaggressive, "leave me alone" brain lesion, which does not require biopsy because of well-defined MRI characteristics. Surgery is indicated only in symptomatic cases. We consider that this lesion was revealed by his seizure, most probably provoked (with normal video EEG recording) by the consumption of a lot of alcohol, illicit drugs, and sleep loss after a club party. We recommended close monitoring, but our patient preferred the surgery. Our case added more imaging details corroborated with the histopathology features of MVNT. FLAIR images revealed hypointense nodules surrounded by hyperintense peripheral rings and areas of high signal intensity between the nodules, which correspond to the histopathological architecture. To our knowledge, this is the first case of MVNT with diffusion tensor imaging and fiber tractography imaging studies.

A rare cause of adult's epileptic crisis: Infratentorial multinodular and vacuolating neuronal tumor.

Multinodular and vacuolating neuronal tumor (MVNT) of the cerebrum is a rare and benign lesion which has been recently included in World Health Organization Classification of the central nervous system tumors. Another entity of lesions would present the same radiological characteristics; however, it would be in the posterior fossa, hence its name: infratentorial multinodular and vacuolating neuronal tumor. They are frequently characterized by the presence of cystic (or cyst-like) nodular lesions and may show cortical involvement. They mainly can be differentiated from other cystic entities, by their clustered and unchanging nature over time. We present the case of a 54-year-old patient who has consulted for epileptic seizures. Magnetic Resonance Imaging showed a multicystic-looking mass involving the vermis and the left cerebellar hemisphere that had no changes at follow-up in the last year suggestive of infratentorial multinodular and vacuolating neuronal tumor.

A cell-based ELISA as surrogate of virus neutralization assay for RBD SARS-CoV-2 specific antibodies.

SARS-CoV-2, the cause of the COVID-19 pandemic, has provoked a global crisis and death of millions of people. Several serological assays to determine the quality of the immune response against SARS-CoV-2 and the efficacy of vaccines have been developed, among them the gold standard conventional virus neutralization assays. However, these tests are time consuming, require biosafety level 3 (BSL3), and are low throughput and expensive. This has motivated the development of alternative methods, including molecular inhibition assays. Herein, we present a safe cell-based ELISA-virus neutralization test (cbE-VNT) as a surrogate for the conventional viral neutralization assays that detects the inhibition of SARS-CoV-2 RBD binding to ACE2-bearing cells independently of species. Our test shows a very good correlation with the conventional and molecular neutralization assays and achieves 100% specificity and 95% sensitivity. cbE-VNT is cost-effective, fast and enables a large-scale serological evaluation that can be performed in a BSL2 laboratory, allowing its use in pre-clinical and clinical investigations.

Multinodular and Vacuolating Neuronal Tumor: Incidental Diagnosis of a Rare Brain Lesion.

Multinodular and vacuolating neuronal tumor (MVNT) is a rare benign brain lesion, commonly found in middle-aged adults. The patients experience a range of symptoms from being asymptomatic to epileptic seizures, with headache being the most common symptom. Here we report a case of an incidental diagnosis of MVNT in a young female. A 25-year-old female with a past medical history of occasional headaches without seizures or any focal neurological deficit presented after a motor vehicle rollover. The MRI brain revealed an incidental finding of a subcortical lesion in the right parietal lobe with T2-FLAIR (fluid-attenuated inversion recovery) hyperintensity between the cystic portions, indicative of a possible MVNT, with a less probable chance of dysembryoplastic neuroepithelial tumor based on the subcortical location of the lesion. No neurosurgical intervention was recommended. With one-year follow-up, no changes were noted on neuroimaging, and the patient remained stable without any neurological symptoms. The MVNT is a rare brain lesion that presents with benign features. In patients with epileptic symptoms, surgical resection of the lesion can be curative. However, in asymptomatic patients, careful monitoring may be sufficient, as described in this case.

Multinodular and vacuolating neuronal tumor associated with focal cortical dysplasia in a child with refractory epilepsy: a case report and brief review of literature.

Multinodular and vacuolating neuronal tumor (MVNT) is a rare newly identified benign lesion, firstly included in the World Health Organization classification of tumors of the central nervous system in 2016, whose neoplastic or dysplastic nature remains unclear but with a distinctive cytoarchitectural pattern and radiological features. It is usually discovered as late-onset refractory epilepsy, headache related, or an incidental lesion of adulthood. As it is typically a stable disease, many opt for follow-up, as long as it keeps remaining asymptomatic, leaving surgery for refractory epilepsy, neurological deficits, or intracranial hypertension symptoms. A subtotal or complete resection seems to control seizures and neurological manifestations. We herein present the case of a child with refractory epilepsy related to MVNT and focal cortical dysplasia, a dual pathology case in a less frequent age group and without the typical radiological imaging. We report its radiologic features, histologic description, and management, and we present a brief literature review on MVNT focusing on the pediatric cases reported. MVNT should now be another probable low-grade epilepsy-associated lesion (LEAT) in patients of all ages, with a benign and stable course as it constitutes a curable cause of focal epilepsy. As all the refractory cases, surgery should be indicated after a comprehensive evaluation of a multidisciplinary epilepsy surgery team.

Infratentorial Multinodular and Vacuolating Neuronal Tumor or Multinodular and Vacuolating Posterior Fossa Lesions of Unknown Significance? Clinico-Radiologic Findings from 2 Cases.

BACKGROUND: Infratentorial multinodular lesions resembling multinodular and vacuolating neuronal tumor of the cerebrum (MVNT) have been indicated in literature with 2 different names reflecting alternative perspectives: multinodular and vacuolating posterior fossa lesions of unknown significance (MV-PLUS), suggesting that these lesions may belong to a new entity, and MVNT of the brain, assuming that they actually correspond to infratentorial MVNT. Because of the limited number of cases reported and the absence of histopathologic data, it is unclear which denomination should be used. CASES DESCRIPTION: Two patients, a 41-year-old man (case 1) suffering headache and a 44-year-old man (case 2) with vertigo, underwent magnetic resonance imaging (MRI) examination. MRI showed, in both cases, multinodular lesions involving the vermis, broadly extending to the superior part of the right cerebellar hemisphere in case 1, and involving the superior paravermian part of the left cerebellar hemisphere in case 2. The follow-up period was 3 years in case 1 and 14 years in case 2. CONCLUSIONS: Infratentorial lesions show nodules with cystic or cyst-like signal intensity on MRI, a feature infrequently reported in supratentorial MVNT, and may involve the cortex. No variations were noted during a prolonged follow-up supporting the benign behavior of these lesions.

Multinodular and vacuolating neuronal tumor (MVNT): A presumably incidental and asymptomatic case in an intractable epilepsy patient.

INTRODUCTION: Multinodular and vacuolating neuronal tumor (MVNT) had been initially described as an epilepsy-related brain tumor, but recent studies demonstrated it could be found incidentally in non-epilepsy patients. CASE REPORT: A 33-year-old woman with intractable post-encephalitis epilepsy presented a cluster of multinodular T2 hyperintensity in the left temporal lobe, which was very similar to the characteristics of MVNT. Long-term video electroencephalogram demonstrated that the habitual seizures were originated from bilateral temporal area and the interictal epileptic discharges were seen multifocally, although the lesions with MVNT appearance were localized in the left temporal lobe. It was presumed that the epilepsy in this patient was due to encephalitis in the past, and the link between the lesions and the epilepsy in this patient seemed weak. CONCLUSION: Although MVNT had been considered as an epilepsy-related brain tumor, we suggest it is not necessarily preferable to perform surgical resection of MVNT even on patients with epilepsy, unless epileptic foci are highly related to MVNT.

Multinodular and Vacuolating Neuronal Tumor.

BACKGROUND: Multinodular and Vacuolating Neuronal Tumor (MVNT) of the cerebrum is a benign lesion described recently in the WHO CNS tumours in 2016. Although this tumour is uncommon, clinicians should be acquainted with the possible presentation and imaging findings. CASE REPORT: We present a case of a young gentleman whose only symptom was absence seizures. Brain imaging showed lesions, compatible with this rare diagnosis. CONCLUSION: Our description of imaging findings on MRI highlights the characteristic cystic appearances of note in the right occipital lobe, in contrast to the temporal lobe as the predominant location found in previous cases.

Natural history of lesions with the MR imaging appearance of multinodular and vacuolating neuronal tumor.

PURPOSE: Multinodular and vacuolating neuronal tumor (MVNT) have been recently added to the WHO classification of CNS tumors and has not been extensively reported upon in the radiological literature. We report the first radiological and the largest series of cases, aiming to highlight the natural history of lesions with the imaging appearance of MVNT with long follow-up time. METHODS: In this retrospective study, we collected cases with the imaging appearance of MVNT. All lesions were evaluated by using routine MR imaging, with follow-up of up to 93 months. Patient demographics, clinical course, and MRI features of the lesions were recorded. RESULTS: Twenty-four subjects were enrolled, f/m = 16:8, age range 24-59 years, with a median age of 45 years. The patients' symptoms were often episodic and most frequently due to headaches in 12 (50%), visual symptoms in 6 (25%), seizures in 5 ± 1 (20-25%), paresthesia in 4 (~17%), cognitive difficulties in 4 (~17%), in addition to other variable neurological symptoms, or incidental. A total of 30 lesions identified, 77% of the lesions had gadolinium-enhanced MRI and only 13% showed enhancement. A 6.7% of the lesions that had MRI followed up showed progression, while the rest remained stable up to 93 months interval. All patients had intact neurological examinations (except one case that was diagnosed with optic neuritis), were managed conservatively, and did well. CONCLUSION: The natural history of lesions with imaging features of MVNT is overall stable from a clinical and imaging appearance over time.