Wednesday, May 30, 2018
Moving beyond histologic grading of IDH-wildtype diffuse astrocytic gliomas
Despite the fact that the most recent update of the World Health Organization (WHO) classification of central nervous system tumors was published only two years ago, the data is already showing that we are moving beyond that classification system when if comes to IDH-wildtype diffuse astrocytomas. The concept of an "integrated diagnosis" in the setting of IDH-wildtype histologic grade II and III tumors has already been eclipsed in the literature by the primacy of the genetic signature over histologic appearance in predicting outcome. In the near future, diffuse IDH-wildtype astrocytic gliomas with (1) combined whole chromosome gain of 7 and loss of 10, and/or (2) EGFR amplification will be designated as equivalent to WHO grade IV gliomas. Histologic grades for such tumors will be stricken from the top diagnostic line so as to avoid unfounded reassurance that these tumors will behave in any way other than very aggressively.