History: A 30-year-old woman presents with vertigo.
A contrast-enhanced MRI scan of the brain was performed. Axial T2-weighted, T2-weighted fluid-attenuated inversion-recovery (FLAIR), and T1-weighted and T1-weighted postcontrast MR images are shown below. 颅脑MR增强扫描：轴位T2WI、T2-FLAIR、T1WI及T1WI增强图像如下所示。
MRI demonstrates a cluster of well-delineated, variable-sized FLAIR/T2-hyperintense cysts within the left frontal subcortical white matter, without obvious mass effect or postcontrast enhancement.
- Multinodular and vacuolating neuronal tumor
- Dysembryoplastic neuroepithelial tumor
- Focal cortical dysplasia
- Tumefactive perivascular spaces
- Pilocytic astrocytoma
- Pleomorphic xanthoastrocytoma
Diagnosis: Multinodular and vacuolating neuronal tumor (MVNT)
Pathophysiology, epidemiology, and clinical presentation：
Multinodular and vacuolating neuronal tumors are a more recently characterized World Health Organization (WHO) grade 1 central nervous system neoplasm. This rare entity has only been described in several case series. They are characterized as a benign, mixed glial neuronal lesion consisting of nodules of disorganized neuronal cells located near the subcortical white matter. They are associated with long-term seizures in adults in about 30% of patients, but they are most often found incidentally and are considered “do not touch” or “leave me alone” lesions if not associated with intractable epilepsy.
- They are difficult to identify on CT but may exhibit hypoattenuation.
- On MRI, they are seen as a subcortical cluster of tiny, cystic, nodular lesions with associated T2/FLAIR signal abnormality (and mildly T1 hypointensity).
- They are usually seen in the deep cortical ribbon and superficial subcortical white matter.
- They rarely enhance (approximately 3% to 10% of cases) with stippled faint enhancement.
- They should not exhibit restricted diffusion or abnormal susceptibility.
- They rarely progress/increase in size.
- 在MRI上表现为T2 / FLAIR信号异常（T1轻度低信号）的皮层下簇状微小囊性结节性病变；
They are slow-growing/indolent, and if not associated with refractory epilepsy, they are considered a “leave me alone” lesion.
They are usually just followed with imaging, but they can be resected if they are associated with intractable epilepsy.