Gastric neuroendocrine tumor: A practical literature review

Table 3 Types of gastric neuroendocrine tumors

	Type I	Type II	Type III
Prevalence, %	70-80	5-10	10-20
Background	Chronic atrophic gastritis	Gastrinomas (Zollinger-Ellison syndrome)	Normal mucosa
Other syndromes	Autoimmune polyglandular syndrome	MEN-1 syndrome
Number of lesions	Multiple	Multiple	Single
Site of tumor	Fundus/body	Fundus/body	Fundus/body
Cell of origin	ECL	ECL	ECL, EC or X cell
Serum gastrin levels	Elevated	Elevated	Normal
Gastric PH	High	Low	Normal
Underlying mucosa	Atrophic	Hypertrophic	Normal
Size of tumors, usual	1-2 cm	1 cm	> 2 cm
Invasion	Rare	More common	Common
Metastases
Lymph nodes	5%-10%	10%-20% (duodenal tumors)	50%-100%
Liver	2%-5%	10%	22%-75%
Prognosis	Excellent	Very good	Similar to gastric adenocarcinoma

Adapted from[18]. ECL: Enterochromaffin-like; EC: Endocrine.