Magnetic Resonance Imaging Findings in Patients with Multinodular Vacuolating Neuronal Tumors

Objective: Multinodular vacuolating neuronal tumor (MVNT) is a rare entity that radiologists should recognize based on its unique imaging characteristics. We aimed to present the imaging findings of 26 patients diagnosed with MVNT. Materials and Methods: The brain MRI findings of 26 patients with a pre-diagnosis of multinodular vacuolating neuronal tumor (MVNT) were retrospectively evaluated across five centers. Conventional MRI sequences were used for all patients. Additionally, diffusion MRI images were obtained for 25 patients, and contrast-enhanced sequences were performed on 19 patients. Results: The mean age of the patients was 39.7 years. The lesion was located in the cerebrum in 25 patients (96.15%) and in the cerebellum in 1 patient (3.85%). When classified by location, the most common site was the left frontal lobe, observed in 6 patients (23.07%). In 1 patient (3.85%), the lesion was located in the left cerebellum, classified as MVNT/MV PLUS. The long axis of the lesion was measured in the axial plane, with an average size of 18.6 mm. On T1-weighted images (T1W), the lesion was isointense in 23 patients (88.46%) and hypointense in 3 patients (11.54%). On T2-weighted (T2W) and FLAIR sequences, the lesion was hyperintense in all patients. Diffusion-weighted images were obtained in 25 patients; on b1000 sequences, the lesion was hyperintense in 20 patients (80%), isointense in 4 patients (16%), and hypointense in 1 patient (4%). Contrast-enhanced sequences were acquired in 19 patients, with no enhancement observed in any case. Conclusion: Conventional MRI is the primary imaging modality for diagnosing multinodular vacuolating neuronal tumor (MVNT), as its imaging features are characteristic. In addition to these features, diffusion imaging may aid in the diagnosis of MVNT.