Editorial
Copyright ©2006 Baishideng Publishing Group Co.
World J Gastroenterol. Sep 14, 2006; 12(34): 5440-5446
Published online Sep 14, 2006. doi: 10.3748/wjg.v12.i34.5440
Table 1 Classification of neuroendocrine tumors of the pancreas (WHO classification 2004)[41]
1Well-differentiated neuroendocrine tumor
• Benign: confined to pancreas, < 2 cm in size, nonangioinvasive, ≤ 2 mitoses/HPF and ≤ 2% Ki-67-positive cells
- Functioning: insulinoma
- Nonfunctioning
• Benign or low grade malignant (uncertain malignant potential): confined to pancreas, ≥ 2 cm in size, > 2 mitoses/HPF, > 2% Ki-67-positive cells,  or angioinvasive
- Functioning: gastrinoma, insulinoma, VIPoma, glucagonoma, somatostatinoma, or ectopic hormonal syndrome
- Nonfunctioning
2Well-differentiated neuroendocrine carcinoma
• Low grade malignant: invasion of adjacent organs and/or metastases
- Functioning: gastrinoma, insulinoma, glucagonoma, VIPoma, somatostatinoma or ectopic hormonal syndrome
- Nonfunctioning
3Poorly-differentiated neuroendocrine carcinoma
• High grade malignant