TUMORS OF STOMACH
BENIGN TUMORS
Polyps are the most common benign tumors of stomach. Polyps may develop as a result of
epithelial or stromal cell hyperplasia, inflammation, ectopia, or neoplasia.
1. Inflammatory and Hyperplastic polyps
Approximately 75% of all gastric polyps are inflammatory or hyperplastic polyps
Chronic gastritis that initiates the injury and reactive hyperplasia that cause polyp growth
If associated with H. pylori gastritis, polyps may regress after bacterial eradication.
Risk of dysplasia is increased in polyps larger than 1.5 cm.
2. Fundic Gland Polyps
Occur sporadically and in individuals with familial adenomatous polyposis (FAP).
Prevalence increased recently because of increasing use of PPIs which inhibit acid
secretion → increased gastrin secretion → increased oxyntic cell growth.
Fundic gland polyps occur in the gastric body and fundus
Composed of cystically dilated glands lined by Parietal and Chief cells.
, MALIGNANT TUMORS
1. Gastric Adenoma
Represent up to 10% of all gastric polyps.
Usually between 50 and 60 years of age, and males are affected three times more often than
females. Incidence of adenomas is increased in individuals with FAP.
Almost always associated with chronic gastritis with atrophy and intestinal metaplasia.
Risk of adenocarcinoma increased in lesions > 2cm in diameter.
Usually solitary lesions in antrum.
By definition, all gastrointestinal adenomas exhibit epithelial dysplasia, which can be classified
as low or high grade.
Gastric adenomas are premalignant neoplastic lesions with high risk of malignant
transformation.
2. Gastric Adenocarcinoma
Adenocarcinoma is the most common malignancy of the stomach, comprising more than 90% of
all gastric cancers.
Epidemiology
In Japan, Chile, Costa Rica, and Eastern Europe, the incidence is up to 20-fold higher than in
North America, northern Europe, Africa, and Southeast Asia.
Gastric cancer is more common in lower socioeconomic groups and in individuals with
multifocal mucosal atrophy and intestinal metaplasia.
Pathogenesis
H. pylori: Chronic gastritis, most commonly due to H. pylori infection, promotes the development and
progression of cancers ( Intestinal type ).
EBV: While H. pylori is most commonly associated with gastric cancer, approximately 10% of gastric
adenocarcinomas are associated with Epstein-Barr virus (EBV) infection.
BENIGN TUMORS
Polyps are the most common benign tumors of stomach. Polyps may develop as a result of
epithelial or stromal cell hyperplasia, inflammation, ectopia, or neoplasia.
1. Inflammatory and Hyperplastic polyps
Approximately 75% of all gastric polyps are inflammatory or hyperplastic polyps
Chronic gastritis that initiates the injury and reactive hyperplasia that cause polyp growth
If associated with H. pylori gastritis, polyps may regress after bacterial eradication.
Risk of dysplasia is increased in polyps larger than 1.5 cm.
2. Fundic Gland Polyps
Occur sporadically and in individuals with familial adenomatous polyposis (FAP).
Prevalence increased recently because of increasing use of PPIs which inhibit acid
secretion → increased gastrin secretion → increased oxyntic cell growth.
Fundic gland polyps occur in the gastric body and fundus
Composed of cystically dilated glands lined by Parietal and Chief cells.
, MALIGNANT TUMORS
1. Gastric Adenoma
Represent up to 10% of all gastric polyps.
Usually between 50 and 60 years of age, and males are affected three times more often than
females. Incidence of adenomas is increased in individuals with FAP.
Almost always associated with chronic gastritis with atrophy and intestinal metaplasia.
Risk of adenocarcinoma increased in lesions > 2cm in diameter.
Usually solitary lesions in antrum.
By definition, all gastrointestinal adenomas exhibit epithelial dysplasia, which can be classified
as low or high grade.
Gastric adenomas are premalignant neoplastic lesions with high risk of malignant
transformation.
2. Gastric Adenocarcinoma
Adenocarcinoma is the most common malignancy of the stomach, comprising more than 90% of
all gastric cancers.
Epidemiology
In Japan, Chile, Costa Rica, and Eastern Europe, the incidence is up to 20-fold higher than in
North America, northern Europe, Africa, and Southeast Asia.
Gastric cancer is more common in lower socioeconomic groups and in individuals with
multifocal mucosal atrophy and intestinal metaplasia.
Pathogenesis
H. pylori: Chronic gastritis, most commonly due to H. pylori infection, promotes the development and
progression of cancers ( Intestinal type ).
EBV: While H. pylori is most commonly associated with gastric cancer, approximately 10% of gastric
adenocarcinomas are associated with Epstein-Barr virus (EBV) infection.
