Table 1. WHO classification of neuroendocrine tumors 2010: Functional classification.

Name	Cell type	Hormones secreted	Malignancy (%)	Pancreatic involvement (%)	Syndrome
Insulinoma	B	Insulin	10	99	Hypoglycemic symptoms, whipple triad
Gastrinoma	G	Gastrin	60–90	25	ZES (peptic ulcer, epigastric pain, diarrhea)
VIPoma	D1	Vasoactive intestinal peptide	40–70	90	Watery diarrhea, hypokalemia, dehydration, achlorhydria
Glucagonoma	A	Glucagon	50–80	100	Rash, migratory erythema, diabetes mellitus, cachexia
Somatostatinoma	D	Somatostatin	70	55	Diabetesmellitus, cholelithiasis, and diarrhea
GRFoma	PP	Growth hormone-releasing hormone	60	30	Acromegaly
ACTHoma	NT	ACTH	95	4–16	Cushing's syndrome
Carcinoid	EC	Serotonin, tachykinins	60–88	1	Diarrhea, flushing, pain, asthma, and heart disease