New insights in diagnosis and treatment of gastroenteropancreatic neuroendocrine neoplasms

Table 2 Clinicopathologic characteristics of gastric neuroendocrine tumor

	Type 1	Type 2	Type 3
Relative frequency (%)	70-80	5-6	10-15
Gender	F > M	F = M	M > F
Cell of origin	ECL	ECL	ECL, EC, etc.
Associated disease	AMAG; Pernicious anemia	MEN1; ZES	None (Sporadic)
Site of tumors	Fundus and corpus	Fundus and corpus, occasionally antrum	Anywhere
Size of tumors	< 1 cm	< 2 cm	2-5 cm
Number of tumors	Multiple	Multiple	Single
Plasma gastrin level	High	High	Normal
Gastric acid output	Low or absent	High	Normal
Metastatic rate (%)	2-5	10-30	50-100
Tumor related death (%)	Approximately 0	< 10	25-30

ECL: Enterochromaffin-like cell; EC: Enterochromaffin cell; F: Female; M: Male; AMAG: Autoimmune metaplastic atrophic gastritis; MEN1: Multiple endocrine neoplasm type 1; ZES: Zollinger-Ellison syndrome.