Gastric carcinomaGastric carcinoma

Carcinoma is the most important and the most common (90% to 95%) of malignant tumors of the

stomach. Next in order of frequency are lymphomas (4%), carcinoids (3%), and mesenchymal tumors (2%),

* Epidemiology.•Gastric carcinoma is the second most common tumor

in the world. Its incidence, however, varies widely, being particularly high in countries such as Japan.

•Male-to-female ratio of about 2:1.

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Gastric Cancer

Diet

H. pylori Genetic factors

* Pathogenesis of Gastric Cancer* Pathogenesis of Gastric Cancer

Precancerous changes

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1. Helicobacter pylori Infection. 1. Helicobacter pylori Infection.

• Chronic infection with H. pylori generally

increases the risk for developing gastric

carcinoma by five- to six-fold.

• The bacterial infection causes chronic gastritis,

followed by atrophy, intestinal metaplasia,

dysplasia, and carcinoma.

2. Diet: 2. Diet:

• Nitrites derived from nitrates (preserved

food).

• Smoked and salted foods, pickled vegetables,

chili peppers.

• Lack of fresh fruit and vegetables.

3. Genetic factors: 3. Genetic factors:

• Slightly increased risk with blood group A.

• Family history of gastric cancer.

• Familial gastric carcinoma syndrome (E-cadherin

mutation).

4. Precancerous lesions:4. Precancerous lesions:

1. Gastric dysplasia:

- About 10% of these cases progress to gastric carcinoma

specially high-grade dysplasia.

2. Atrophic gastritis: which associated with intestinal

metaplasia.

3. Chronic gastric peptic ulcer.

4. Gastric adenoma.

* Morphology of gastric carcinoma: * Morphology of gastric carcinoma:

• The location of gastric carcinomas within the stomach is as

follows:

Cardia ,pylorus and antrum : 50% to 60%.

The remainder in the body and fundus: 25%

• The lesser curvature is involved in about 40% and the greater

curvature in 12%.

• Thus, a favored location is the lesser curvature of the antro

pyloric region.

* Gross morphology of gastric carcinoma:* Gross morphology of gastric carcinoma:

A. Exophytic type: forming a polypoid (fungating) mass.

B. Flat or depressed type (infiltrative):

-Localized.

-Diffuse (linnitus plastica).

C. Excavating type: forming malignant ulcer.

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Polypoid (fungating)

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Ulcerating (malignant ulcer)

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Linnitus plastica

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* Histologic subtypes of gastric carcinoma:* Histologic subtypes of gastric carcinoma:

1. Intestinal type:

- Composed of neoplastic intestinal glands resembling those of

colonic adenocarcinoma which permeate the gastric wall.

2. Diffuse type (Signet ring):

- Composed of malignant mucous cells, which generally do not

form glands, but rather permeate the gastric wall as individual

cells.

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1. Gastric carcinoma; Intestinal type:1. Gastric carcinoma; Intestinal type:

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1. Gastric carcinoma; Intestinal type:1. Gastric carcinoma; Intestinal type:

Gastric carcinoma: diffuse type.Gastric carcinoma: diffuse type.

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* Complications of gastric carcinoma:* Complications of gastric carcinoma:

1. GIT bleeding.2. Gastric obstruction.3. Gastric perforation specially in the ulcerative type.4. Spread:

•Direct.•Lymphatic: especially to the left supraclavicular lymph node (Virchow’s sign).•Blood.•Transcoelomic (Krukenberg’s tumor).

* Clinical Features of gastric carcinoma:* Clinical Features of gastric carcinoma:

• Gastric carcinoma is an insidious disease that is generally

asymptomatic until late in its course.

• The symptoms include weight loss, abdominal pain, anorexia,

vomiting, altered bowel habits, and less frequently dysphagia,

anemic symptoms, and hemorrhage.

• As these symptoms are essentially non-specific, early

detection of gastric cancer is difficult.

* Diagnosis of gastric adenocarcinoma: * Diagnosis of gastric adenocarcinoma:

1. Clinical features:

2. Endoscopy: for evaluating both gross and microscopic

appearance of the tumor by taking biopsy for definitive

diagnosis.

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References:Robbins and Cotran’s: Pathologic Basis of Disease. Seventh edition.