TABLE 1.

Diffuse Glioma ICD-O-3 Coding and Histologies Presently Available in Registry-Derived Databases from 2010 to 2015 (i.e. pre-WHO 2016 Classification)

ICD-O-3 Code/Behavior	ICD-O-3 Histology	n	% with WHO grade	% with 1p/19q codeletion data
9380/3	Glioma, malignant	3,956	23.2	4.0
9381/3	Gliomatosis cerebri	217	49.8	6.9
9382/3	Mixed glioma	2,688	94.8	43.0
9400/3	Astrocytoma, NOS	5,135	81.4	11.9
9401/3	Astrocytoma, anaplastic	5,977	94.2	15.2
9410/3	Protoplasmic astrocytoma	20	95.0	10.0
9411/3	Gemistocytic astrocytoma	436	93.3	12.2
9420/3	Fibrillary astrocytoma	924	93.2	8.7
9440/3	Glioblastoma, NOS	48,730	82.8	5.4
9441/3	Giant cell glioblastoma	422	90.3	5.2
9442/3	Gliosarcoma	1,177	89.2	3.7
9450/3	Oligodendroglioma, NOS*	3,456	91.9	44.9
9451/3	Oligodendroglioma, anaplastic	1,580	95.7	46.7
	Total	74,718	81.8	10.7

“/3” behavior code designates a malignant tumor; NOS: Not otherwise specified;

^*In ICD-O-3, this diagnosis is synonymous with oligodendroglioma, diffuse.