12. The benign and malignant tumors of the stomach

What are polyps?

Fleshy growths found on mucous membranes throughout the body

- benign tumor-like lesions

Non-neoplastic polyps in the stomach?

- Hyperplastic polyps

- Fundic gland polyps

- Hamartomatous polyps

- Inflammatory fibroid polyp

- Xanthoma of the stomach

Hyperplastic polyps?

1-2cm big and located in the antrum as multiple polyps

- benign and not precancerous

What are hyperplastic polyps of the stomach associated with?

Chronic gastritis

Fundic gland polyps?

Well circumscribed polyps that are composed of dilated irregular glands

- can occur sporadically or in people with familiar adenomatous polyposis, and are usually located in the fundus and corpus

Why does occurence of fundic gland polyps increase?

Occurence has increased due to increased use of proton-pump inhibitor therapy

- will result in the increase of gastrin release and glandular hyperplasia by gastrin

What are hamartomas?

A noncancerous tumor made of an abnormal mixture of normal tissues and cells from the area in which it grows

Hamartomatous polyps?

Polyps consisting of disorganized cells and tissue which are usually found at the site of where polyps lie

- mostly part of polyposis syndromes

Different polyposis syndromes?

- Peutz-Jeghers-syndrome

- Juvenile polyposis

Inflammatory fibroid polyp?

Polyps which basically are submucos granulomas with infiltration of eosinophils

What does the inflammatory fibroid polyp consist of?

Consist of a mixture of stromal and inflammatory cells

What are xanthomas?

"Lipid islands"

Adenomas of the stomach?

= Adenomatous polyps

- Polyps that show dysplasia

Adenoma of the stomach mostly occur in?

Occur in patients with a history of chronic gastritis with atrophy and intestinal metaplasia

What is the most common cancer found in the stomach?

Adenocarcinoma

How can we classify gastric adenocarcinoma?

- Laurens classification

- Mings classification

- Bormanns classification

Lauren classification of gastric adenocarcinoma? what is it based on?

- Intestinal type

- Diffuse type

Based on their location in the stomach, and their gross and histological morphology

The intestinal type?

Has glandular structures

- has a better prognosis than the diffuse type

Intestinal type, high grade vs low grade?

- High grade = poor differentiation

- Low grade = high differentiation

The diffuse type?

Has a special cell type called signet ring cells

- more aggressive than the intestinal type

Histology of signet ring cells?

- Nuclei compressed on the periphery

- Have large mucin-containing vacuoles in the cytoplasm

Mings classification of gastric adenocarcinoma?

Tell us how the cancer is expanding

- expansive = exophytic growth into the lumen

- infiltrative growth

Bormann classification of gastric adenocarcinoma?

1. Polypoid type

2. Fungative type

3. Ulcerative type

4. Diffuse growth type

Polypoid type?

Protrudes into the lumen like a polyp

Fungative type?

Protrudes and has an ulcerative surface

Ulcerative type?

Non-protruding with an ulcerative surface

Diffuse growth type?

Diffusely thickened gastric wall

Other tumors of the stomach?

- Gastrointestinal stroma tumor = GIST

- Lymphomas

- Leiomyoma

- Schwannoma

- Kaposi sarcoma

What is GIST?

Most common mesenchymal tumor of the stomach

- originate from the Cajal-cells

Lymphomas of the stomach?

- MALT lymphoma

- Diffuse large B-cell lymphoma

- Mantle cell lymphomas

MALT lymphoma?

Cancer originating from B-cells in the MALT

- the risk factor is H.pylori, which secrete CagA that leads to B-cell proliferation and autoreactive B-cells