Re-evaluation of nondiagnostic biopsies of suspected low-grade glioma using isocitrate dehydrogenase 1 mutation immunohistochemistry

摘要

Mutations in the isocitrate dehydrogenase 1 (IDH1) or 2 (IDH2) genes, which involve the citric acid cycle, have been recently identified as common early mutations in low-grade glioma and are rarely found in primary glio-blastoma. The IDH1 and IDH2 mutations are beginning to play a role in the classification of gliomas and to provide clues into gliomagenesis. This mutation is commonly present in low-grade, infiltrating glial tumors or tumors that had progressed secondarily from low-grade lesions, and is acquired early in development, before accumulating TP53 or lp/19q mutations.This suggests an origin from a common glial progenitor cell for these tumors but a different molecular and genetic origin for primary glioblastomas.This mutation also is generally unique to malignant glial processes, with no evidence of this mutation being found in nonneoplastic conditions, which include gliosis, infectious changes, vascular changes, demyelinating changes, and radiation changes. However, mutations have also been shown to be present in cartilaginous tumors and some myeloproliferative neoplasms, and there have been rare mutations described in primary glioblastoma, primitive neuroepithelial tumors, and dysembryoplastic neuroepithelial tumors (DNT).