Multinodular and vacuolating neuronal tumor of the cerebrum.

Multinodular and vacuolating neuronal tumors of the cerebrum (MVNT) are superficial neuronal tumors in adults that were first documented in 2013. Herein, we report a case of MNVT involving a 37-year-old man who presented with an epileptogenic, superficial solid lesion in the left parietal lobe. Histomorphology of the resected specimen was characterized by nodular lesions with vacuolation. Nodules comprised irregular proliferation of neuronal cells, which ranged from ganglion-like forms to those with indistinct lineage. Immunohistochemical analysis showed that the lesional cells stained positively for HuC/HuD, synaptophysin, and Olig2, and negatively for NeuN, neurofilament, chromogranin A, GFAP, CD34, IDH1(R132H), and BRAF(V600E). Eighteen months following surgery, the patient is well and without neurological deficits. MVNTs are distinctive tumors that should be differentiated from ganglion cell tumors, dysembryoplastic neuroepithelial tumors, and malformation of cortical development.