MKI67 and anaplastic ganglioglioma: The most prominent difference when comparing AGGL to PT and NB tissues was a very low total content of GGs, 4.6 and 5.7 times lower, respectively, which possibly reflects the highly invasive nature of the tumor that transformed in only six months from low malignancy ganglioglioma (grade I and Ki-67 index 3%) to anaplastic ganglioglioma (grade III and Ki-67 index 25%).