Gastric Neoplasms Overview

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Questions and Answers

What is the primary cause of increased incidences of fundic gland polyps?

Widespread use of proton pump inhibitors leading to increased gastrin secretion.

How is high-grade dysplasia classified in relation to adenocarcinoma?

High-grade dysplasia is equivalent to in situ carcinoma or intraepithelial neoplasia.

What are the primary histological features of dysplasia observed in gastric epithelium?

Variations in epithelial cell size, shape, and orientation, along with coarse chromatin texture and nuclear enlargement.

What key risk factor increases the likelihood of malignant transformation in gastric adenomas?

The size of the adenoma, particularly those greater than 2 cm in diameter. Signup and view all the answers

How do chronic gastritis and intestinal metaplasia correlate with gastric adenocarcinoma?

Chronic gastritis with atrophy and intestinal metaplasia provides a background for the development of gastric adenomas and cancer. Signup and view all the answers

How does chronic gastritis contribute to the development of gastric adenocarcinoma?

Chronic gastritis exposes the epithelium to inflammation-related free radical damage, leading to genetic alterations and increased cellular proliferation. Signup and view all the answers

What distinguishes adenomatous polyps from hyperplastic polyps in the context of gastric cancer risk?

Adenomatous polyps have malignant potential, whereas hyperplastic polyps do not. Signup and view all the answers

What role does H.pylori infection play in gastric cancer development?

H.pylori infection induces chronic gastritis, promoting epithelial proliferation and potential cancer progression. Signup and view all the answers

What genetic mutation is significantly associated with familial diffuse gastric cancer?

Germline mutations in CDH1, which encodes E-cadherin. Signup and view all the answers

In what age group do inflammatory and hyperplastic gastric polyps most commonly occur?

These polyps most commonly affect individuals between 50 and 60 years of age. Signup and view all the answers

In which patient demographic is gastric adenoma more prevalent?

Gastric adenoma incidence increases in patients aged 50 to 60 years, especially in males. Signup and view all the answers

What is the significance of polyp size in relation to dysplasia and gastric cancer risk?

There is a significant increase in the risk of dysplasia and potential cancer with polyps larger than 1.5 cm. Signup and view all the answers

Describe the relationship between Helicobacter pylori infection and gastric polyps.

Gastric polyps associated with H. pylori gastritis may regress after the bacterial infection is eradicated. Signup and view all the answers

How does geographic distribution affect the incidence of gastric cancer?

Gastric cancer is more common in lower socioeconomic groups and regions like Japan and Russia. Signup and view all the answers

What are fundic gland polyps, and how are they associated with familial adenomatous polyposis (FAP)?

Fundic gland polyps occur sporadically and in individuals with FAP; while they may show dysplasia, they rarely progress to malignancy. Signup and view all the answers

What is a significant characteristic of EBV-positive gastric adenocarcinomas?

They have clonal EBV episomes, indicating infection may precede neoplastic transformation. Signup and view all the answers

Explain the differences between intestinal type and diffuse type gastric adenocarcinoma.

Intestinal type is characterized by glandular structures, whereas diffuse type often presents as signet ring cells lacking a distinct structure. Signup and view all the answers

What are the two main microscopic types of gastric cancer according to Lauren's classification?

Intestinal type and diffuse type. Signup and view all the answers

What role do neuroendocrine tumors play within the spectrum of gastric neoplasms?

Neuroendocrine tumors are one of the other gastric neoplasms that can arise, often exhibiting distinct morphological characteristics. Signup and view all the answers

How does dysplasia in gastric epithelium relate to regenerative changes due to injury?

Dysplasia can overlap with regenerative changes, making it difficult to distinguish between benign compensatory responses and precancerous lesions. Signup and view all the answers

What type of symptoms may indicate advanced gastric disease?

Weight loss, anorexia, fatigue, and emesis. Signup and view all the answers

Describe the common clinical presentation in the early stages of gastric disease.

Vague epigastric discomfort or indigestion that is constant, nonradiating, and unrelieved by food digestion. Signup and view all the answers

Identify the most common site for extranodal lymphomas and its significance.

The gastrointestinal tract, particularly the stomach, is the most common site for extranodal lymphomas. Signup and view all the answers

What are the morphologic types of gastric carcinoma?

Fungating and ulcerating types. Signup and view all the answers

What is the relationship between H. pylori infection and gastric MALTomas?

H. pylori infection is the most common inducer of gastric MALT and is found in association with most gastric MALTomas. Signup and view all the answers

What role do chronic inflammation and organized lymphoid tissue play in gastric lymphoma?

Extranodal marginal zone B-cell lymphomas usually arise at sites of chronic inflammation and can occur in areas devoid of organized lymphoid tissue. Signup and view all the answers

Explain the significance of MALT in relation to gastric lymphoma.

MALT is typically not present in the normal stomach but can be induced due to chronic gastritis. Signup and view all the answers

What translocation is most commonly associated with gastric MALToma?

The t(11;18)(q21;q21) translocation. Signup and view all the answers

What is the frequency of primary lymphomas among all gastric malignancies?

Nearly 5% of all gastric malignancies are primary lymphomas. Signup and view all the answers

What is the significance of MALTomas in the context of gastrointestinal lymphomas?

MALTomas, or lymphomas of MALT, refer to indolent extranodal marginal zone B-cell lymphomas occurring in the gastrointestinal tract. Signup and view all the answers

Study Notes

Gastric Neoplasms: Benign & Malignant

Gastric Adenocarcinoma
- Intestinal type
  - More common
  - Well-differentiated, glandular
  - Arises in a background of chronic gastritis with atrophy and intestinal metaplasia
- Diffuse (Signet ring)
  - Usually arises in young patients
  - Less differentiated
  - Signet ring cells are a hallmark
  - associated with loss of E-cadherin function
Gastric Polyps
- Found in up to 5% of upper gastrointestinal tract endoscopies
- Inflammatory and Hyperplastic Polyps
  - Most common type (up to 75%)
  - Associated with chronic gastritis
  - Can regress after bacterial eradication
  - Risk of dysplasia increases with size, especially those larger than 1.5 cm
- Fundic Gland Polyps
  - Sporadic or familial (associated with FAP)
  - Can show dysplasia in FAP, but rarely progress to malignancy
  - Increased incidence associated with proton pump inhibitors (likely due to increased gastrin secretion)
- Adenomatous Polyps
  - Precancerous
  - Risk for adenocarcinoma is related to size, especially those greater than 2 cm
  - Overall risk of malignant transformation is higher than with colonic polyps
Precancerous Lesions
- Dysplasia
  - Marked by variations in epithelial cell size, shape, and orientation
  - Can be low-grade or high-grade, with high-grade dysplasia representing in-situ carcinoma
- Adenoma
  - Important precursor to gastric adenocarcinoma
  - Associated with chronic gastritis, atrophy, and intestinal metaplasia
  - Risk for adenocarcinoma is elevated with lesions greater than 2 cm
Etiologic Factors of Stomach Carcinoma
- Socioeconomic level and diet
- High incidence in Japan, but decreasing in the Western world
- Smoked and salted foods
- Low intake of fresh vegetables
- Nitrosamines
- Chronic gastritis with atrophy and metaplasia
- H. pylori infection
- Intestinal reflux
- Blood group A
- Familial history of stomach cancer
Gastric Lymphoma
- Most common site for extranodal lymphomas
- Nearly 5% of all gastric malignancies are primary lymphomas
- Indolent extranodal marginal zone B-cell lymphomas are the most common
- Often referred to as lymphomas of MALT, or MALTomas
- H.pylori infection is the most common inducer of gastric MALT, and therefore is found in association with most gastric MALTomas.

Gastric Carcinoma

- **Adenocarcinoma**
    - Most common malignancy of the stomach (over 90% of gastric cancers)
    - Early symptoms mimic chronic gastritis, often detected in advanced stages
    - **Epidemiology**
        - Geographic distribution varies
        - More common in lower socioeconomic groups
        - Individuals with multifocal mucosal atrophy and intestinal metaplasia have increased risk
    - **Pathogenesis**
        - **Familial Gastric Cancer**
            - Germline mutations in CDH1 (encoding E-cadherin) are associated with familial gastric cancers, particularly of the diffuse type.
            -  Somatic mutations in CDH1 are found in about 50% of sporadic diffuse gastric tumors
        - **Sporadic Intestinal-type Gastric Cancer**
            - Associated with genetic abnormalities, including gain-of-function mutations of b-catenin
            - TP53 mutations are present in the majority of sporadic gastric cancers
        - ***H. pylori*** 
            - Chronic gastritis promotes progression of gastric cancer
        - **Epstein-Barr virus (EBV)**
            - Up to 10% of gastric adenocarcinomas are associated with EBV infection
            - EBV episomes in these tumors are clonal, supporting a link between infection and cancer development
            - TP53 mutations are uncommon in EBV-positive gastric tumors, suggesting a distinct molecular pathogenesis
- **Morphologic types of Gastric Adenocarcinoma**
    - **Macroscopic types (Borrmann I-IV)**
        - Polypoid
        - Ulcerative
        - Ulcerating and infiltrating
        - Infiltrating
    - **Microscopic types (Laurens)**
        - **Intestinal:** glandular forming, distal, better differentiated
        - **Diffuse:** proximal, intracellular mucus, signet ring cells, less differentiated
- **Clinical Presentation**
    - Asymptomatic early on
    - Early symptoms: vague epigastric discomfort/indigestion
    - Advanced disease: weight loss, anorexia, fatigue, emesis, GI bleeding, obstruction

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Description

This quiz covers the key aspects of gastric neoplasms, including benign and malignant types. Focus areas include gastric adenocarcinoma subtypes and various types of gastric polyps. Test your understanding of histopathological characteristics and associated conditions.