Endoscopic ultrasound-guided ethanol ablation of pancreatic neuroendocrine tumours: A case study and literature review

Table 1 World Health Organization classification of pancreatic neuroendocrine tumors

Grade	Ki-67 index (%)	Mitotic count/10 HPF
G1	≤ 2	< 2
G2	3-20	2-20
G3	> 20	> 20
TNM	Size (cm)	Muscularis propria invasion
T1a	< 1	_
T1b	1-2	_
T2	> 2	+

Accordingly to the WHO classification 2010, the higher grade is assumed if the Ki-67 index and mitotic count differ; in the WHO 2010 TNM, the tumor is classified as T2 if it is larger than 2 cm in diameter or if it invades the muscularis propria. T3 and T4 tumors are locally aggressive tumors. WHO: World Health Organization; HPF: High-power field.