Atypical central neurocytoma with anaplastic histological features in the lateral ventricle of a 37-year-old man.

We report a case of atypical central neurocytoma with anaplastic histological features in the lateral ventricle of a previously healthy 37-year-old man. Histologically, the tumor exhibited anaplastic cell morphology, necrosis, increased mitotic activity, and vascular proliferation. The tumor had copy number alterations, but methylation profiling did not provide a match to any known methylation class, and mutation analyses were negative for pathogenic alterations. Atypical central neurocytoma is a challenging and rare diagnosis, and the World Health Organization (WHO) Classification of Tumors has not yet clarified diagnostic criteria for this putative entity. In a literature review, however, atypical central neurocytoma showed increased aggressiveness compared to conventional central neurocytoma, WHO grade 2.