Immunohistochemical surrogates for molecular alterations for the classification and grading of gliomas

Recent advances in molecular diagnostics have led to a better understanding of glioma tumorigenesis, prognosis, and treatment. Therefore, the 2016 WHO Classification of Tumours of the Central Nervous System and more recent literature recommends the incorporation of molecular results in the pathology report. The methods for molecular testing vary among institutions; however, most practicing pathologists utilize a range of immunohistochemical surrogates for molecular alterations in the evaluation of gliomas. This manuscript reviews the clinical aspects and pitfalls of the immunohistochemical stains with diagnostic, prognostic and therapeutic implications in gliomas.