Table 1.

Types of gastric polyps

		Frequency	Risk factors	Associated conditions	Age/sex	Location	Size	Symptoms	Endoscopic features	Neoplastic potential
Good
Fundic gland	Sporadic	80%	Proton-pump inhibitors	None	Middle age/women	Body/fundus	< 8 mm	Asymptomatic	Sessile, smooth surface	Very rare
	Syndromic		Hereditary	Familial adenomatous polyposis, MUTHY	Early age/no sex difference	Body, multiple (> 90%)	< 6 mm	Asymptomatic		Rare
Inflammatory fibroid		Rare (< 0.1%)	Not known	May be familial, Devon polyposis syndrome-associated with PDGFRA mutation	Older (6th-7th decade) (adults/slight predominace in women)	Antrum-pylorus	Mean size 1-5 cm, up to 9 cm	Early satiety or good, sometimes bleeding	Sessile, pedunculated, +/- ulcerated	Very rare
Ectopic pancreas		0.5%-13%	None	None	Not reported	Antrum-prepyloric region	Variable	Incidental	Firm round or oval subepithelial lesion with a central depression	Benign, no follow-up needed
Hamartomatous polyp	Sporadic	1%	Not known	-	Not reported	Anywhere	Variable	Incidental findings	Sessile, differential dx H. pylori	Benign
Bad
Hamartomatous	Syndromic		PJS, Juvenile polyposis syndrome and phosphatase and tensin homolog hamartoma syndrome	STK11 (PJS)	-	-	The 0.1-3 cm (PJS)		-	Lifetime malignancy risk (up to 29%)
Hamartomatous	Solitary		Gastric inverted Hamartomatous Polyps							Common (up to 20%)
Hyperplastic		15%	H. pylori, chronic atrophic gastritis	Not reported	Middle age/no sex difference	Antrum (60%), any site, solitary, more common multiple	Usually < 2 cm, but up to 12 cm	Asymptomatic, incidental findings	Smooth or lobulated, sessile or pedunculated	Dysplasia 15%, cancer risk < 1%
Adenoma		6%-10%	Atrophy, intestinal Metaplasia	None	Middle age/men (intestinal type)	More common, antrum (intestinal type), any site (other types)	Variable (few mm to cm)	Asymptomatic, anemia, bleeding, rarely obstruction	Sessile, pedunculated	Depends on size; histology (high-grade dysplasia 30% at 5 years); likely gene-disrupting 3% at 5 years
Gastric neuroendocrine tumors		< 2% gastric neoplasm
	GNET type 1	80% all G-NET	Autoimmune gastritis	None	Middle age/old	Body, fundus	Small, multiple	Asymptomatic anemia	Reddish	Low (< 1%), locoregional MTS depends on size, grading and mm propria invasion: 5 years survival 100%
	GNET type 2	5%		Gastrinoma (multiple endocrine neoplasia type 1)	Young	Body, fundus	Small, multiple	Diarrhea, abdominal pain bleeding from peptic ulcer	Small, yellow, often multiple ulceration	Lymph node MTS 30% with good prognosis
Ugly
GNET type 3		The 10%-20% all GNET	No predisposing factors	None	Adults/no sex difference	Anywhere, preference antrum	Large, solitary	Asymptomatic	Single lesion	The 50% risk MTS. Survival 70% at 5 years
Early gastric cancer	Sporadic hereditary (1%-3%)		Equal to gastric adenomaE-cadherin gene	None	Adult/old/male	Antrum (50%) corpus (35%), cardia (15%)		Epigastric pain glycemic index bleeding, anemia, vomiting/nausea	Polyp, ulcer	The 5 years survival 75%, the 80% lifetime cancer risk

GNET: Gastro-intestinal neuroectodermal tumor; PJS: Peutz-Jeghers syndrome; H. pylori: Helicobacter pylori; MTS: Metastasis.