Référentiel gliomes diffus de l'adulte de grade OMS II, III et IV : anatomie pathologique et biologie

Pathological diagnosis plays a major role in the therapeutic management of adult diffuse gliomas. It is based on the histopathological analysis of a representative specimen. Therefore pathologists might be aware of the neuroradiological features of the lesions. Pathologists play a major role in the management of biological resources. Pathologists should classify adult gliomas according to WHO 2007 classification (histological subtype and grade). In addition, in order to provide the histomolecular classification of adult gliomas, search for molecular markers of diagnostic, prognostic or predictive of therapeutic responses must be performed by appropriate and validated immunohistochemical and molecular techniques. In all diffuse gliomas, whatever their grade, search for IDH1 R132H and P53 expression is required. Search for IDH1 minor mutations and IDH2 mutations is required in grade II and III IDH1 R132H negative gliomas whereas 1p19q codeletion should be searched for in grade II and III gliomas with an oligodendroglial component. Search for EGFR amplification and MGMT promoter methylation is recommended. It is strongly recommended to fill the standardized form for pathology and molecular features (validated by the French Society of Neuropathology) in all adult diffuse gliomas.