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Copyright ©The Author(s) 2021.
World J Clin Oncol. Oct 24, 2021; 12(10): 897-911
Published online Oct 24, 2021. doi: 10.5306/wjco.v12.i10.897
Table 1 Comparison of 2010 and 2017 World Health Organization classification system for pancreatic neuroendocrine tumors
WHO 2010 Classification system
WHO 2017 Classification system
Ki-67 index (%)
Mitotic index1
Well-differentiated PanNET G1Well-differentiated PanNET G1< 3< 2
Well-differentiated PanNET G2Well-differentiated PanNET G23-202-20
Well-differentiated PanNET G3> 20> 20
Poorly-differentiated PanNEC G3 (i.e. small cell carcinoma, large cell carcinoma)Poorly-differentiated PanNEC G3 (i.e. small cell carcinoma, large cell carcinoma)> 20> 20
MiNENMANEC
Table 2 Imaging features of grade 3 pancreatic neuroendocrine tumors vs grade 3 pancreatic neuroendocrine carcinomas
Grade 3 PanNET
Grade 3 PanNEC
Smaller, more defined lesionsLarger, ill-defined lesions
Absence of ductal dilation or metastatic diseaseDuctal dilation or metastatic disease
Low to moderate homogeneous enhancement on arterial phase imagingHeterogeneous or rim-like enhancement on arterial phase imaging
Hypointense on delayed phase imagingAtypical persistence of enhancement on delayed phase imaging
Higher ADC valuesSignal hyperintensity on diffusion-weighted MRI and lower ADC value
Low uptake on 18F-FDG PET/CTHigh uptake on 18F-FDG PET/CT
Moderate uptake on 68Ga-DOTATATE PET/CTLow uptake on 68Ga-DOTATATE PET/CT