8. GI Pathology - BP Flashcards
What are the types of a gastric polyp?
- Hyperplastic (90%)
- Fundic gland (rare)
- Adenomatous (10%)
What is the epidemiology of intestinal type gastric adenocarcinoma?
Predominance in males; older than 50 years of age.
What is the mechanism of formation of intestinal type adenocarcinoma?
Tumors arise from a precursor lesion - intestinal metaplasia occuring in the background of chronic gastritis.
What are the main risk factors for intestinal-type gastric adenocarcinoma?
- Nitrites, smoked and salted food.
- Cigarette smoke
- Chronic gastritis with intestinal metaplasia
What is vital for staging intestinal-type gastric adenocarcinoma?
Depth of invasion into the wall of the stomach.
What is the gross morphology of intestinal-type gastric adenocarcinoma?
- Ulcer with heaped up margins.
- Polypoid projection.
- Flat or depressed.
What is the microscopic morphology of intestinal-type gastric adenocarcinoma?
Neoplastic and invasive intestinal-type epithelium
What is the epidemiology of diffuse (signet-ring cell) type gastric adenocarcinoma?
No male-female predominance; patients usually present younger than 50yrs of age.
What is the mechanism of formation of diffuse (signet-ring cell) type of gastric adenocarcinoma?
No precursor lesion; signet ring cell tumors do not arise from intestinal metaplasia.
What is the gross morphology of diffuse-type gastric adenocarcinoma?
Diffuse thickening of mucosa with no well-defined mass.
What is linitis plastica?
Thickening of the stomach wall.
What is the microscopic morphology of diffuse-type of gastric adenocarcinoma?
Signet-ring cells (eccentric nucleus with vacuole).
What are the three components used to categorize gastric carcinomas?
- Depth of invasion
- Microscopic appearance
- Histology
What is the Virchow node?
Metastasis of gastric carcinoma to supraclavicular node.
What is Sister Mary Joseph nodule?
Metastatic periumblical nodule.
What is the clinical presentation of gastric carcinoma?
- Abdominal discomfort
- Early satiety
- Nausea and vomiting
- GI hemorrhage
What are the cells of origin of GI stromal tumors (sarcoma of the stomach)?
The intestitial cells of Cajal.
What is the marker commonly associated with GI stromal tumor?
CD117+ (c-kit).
What are the two main non neoplastic polyps of the GI?
- Hyperplastic polyps
2. Peutz-Jeghers polyps
Give a basic description of hyperplastic polyps.
Common polyp of the large intestine, composed of hyperplastic colonic mucosa.
Give a basic description of Peutz-Jeghers polyps.
Hamartomatous polyps, which include muscularis mucosa.
What are the features of Peutz-Jeghers syndrome?
- Autosomal dominant
- Many GI polyps
- Increased pigmentation of the lips and oral mucosa.
- Patients have increased risk for developing pancreatic, breast, lung, and ovarian cancer.
What are the main types of adenomas in the GI?
- Tubular
- Villous
- Tubulovillous
What is the importance of an adenoma in the GI?
Can be precursor of malignancy. Villous > tubular.
What is the epidemiology of colonic adenocarcinoma?
Older adults (>50).
What is the pathogenesis of colonic adenocarcinoma?
Small polyps (adenomas) are dysplastic, and dysplasia can progress to neoplasia.
Mention some risk factors for colonic adenocarcinoma.
- High fat, high refined carbohydrate diet.
- Familial adenomatous polyposis.
- Hereditary non polyposis colon cancer.
What is the mutation associated with familial adenomatous polyposis?
APC gene in 5q21.
What is the importance of familial adenomatous polyposis?
High risk for progression to invasive adenocarcinoma (100% of patients by age 50).
Do we see increased numbers of polyps in hereditary non polyposis colon cancer?
No. (Compared to familial adenomatous polyposis)
What colon adenocarcinomas present sooner?
Left-sided tumors by causing more of an obstruction.
Is adenocarcinoma common in the small intestine?
No.
What is the clinical presentation of colonic adenocarcinoma?
Right-sided lesions –> pain and change in stool caliber.
Left-sided lesions –> iron deficiency anemia due to hemorrhage.
What do we suspect when we see iron deficiency anemia in patients over 50?
Colon cancer until proven otherwise.
What is the usual location of a carcinoid tumor?
- Appendix
- Ileum
- Rectum
- Bronchi
What is the target group of carcinoid tumors?
Older patients.
What hormones can carcinoid tumors secrete?
- Gastrin (Zollinger-Ellison)
- Insulin
- Somatostatin
- Serotonin