Download Gastric cancer

Gastric 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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* Pathogenesis of Gastric Cancer
H. pylori
Genetic factors
Gastric
Cancer
Diet
Precancerous
changes
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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:
• Nitrites
derived from nitrates (preserved
food).
• Smoked and salted foods, pickled vegetables,
chili peppers.
• Lack of fresh fruit and vegetables.
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:
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:
• 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:
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:
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.
1. Gastric carcinoma; Intestinal type:
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1. Gastric carcinoma; Intestinal type:
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Gastric carcinoma: diffuse type.
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* Complications of gastric carcinoma:
1.
2.
3.
4.
GIT bleeding.
Gastric obstruction.
Gastric perforation specially in the ulcerative type.
Spread:
•Direct.
•Lymphatic: especially to the left supraclavicular lymph
node (Virchow’s sign).
•Blood.
•Transcoelomic (Krukenberg’s tumor).
* 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:
1. Clinical features:
2. Endoscopy: for evaluating both gross and microscopic
appearance of the tumor by taking biopsy for definitive diagnosis.
References:
Robbins and Cotran’s: Pathologic Basis of Disease. Seventh edition.
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