[Classification and Molecular Diagnosis of Benign Brain Tumors].

Classification and molecular diagnosis of benign brain tumors, focusing on cranial and pasaspinal nerve tumors, meningioma, mesenchymal, and non-meningothelial tumors involving the central nervous system(CNS)has been reviewed based on the 5 edition of the World Health Organization Classification of Tumors of the Central Nervous System. In sporadic schwannomas, the novel fusion gene , which activates the MAPK pathway, has been discovered. Meningioma shows frequent chromosomal alterations, including at the NF2 locus. Recent genomic studies have investigated mutations in , and in sporadic meningiomas. In the 5 edition, the meningioma should be graded regardless of the subtype. Thus, promoter mutation and homozygous deletion of CDKN2A/B should be evaluated to define grade 2 and 3 meningiomas. In mesenchymal tumors, the term "hemangiopericytoma" has been deleted from solitary fibrous tumors.