Figure 6: Relationship of operative approach and tumor grade according to the proposed new classification system for craniopharyngiomas. AIH: Anterior Interhemispheric, TSR: Transnasal Transsphenoidal. The mean preoperative grade was 2.48 ± 0.63 for TSR approach (n=25), 2.90 ± 0.77 for AIH (n=61), and 3.08 ± 0.67 for pterional approach (n=12). Preoperative grade was significantly different between TSR and AIH approaches, and between TSR and PTR approaches.