Gastric Neoplasia I

Question 1

What are the main types of non-neoplastic gastric polyps?

Answer 1

Inflammatory/hyperplastic poylps and

fundic gland polyps, which

Question 2

What are the neoplastic gastric polyps?

Answer 2

Adenomas-precursors to gastric cancer

Question 3

Describe hyperplastic gastric polyps

Answer 3

These are developed in the presence primarily (60%) in the antrum of the stomach in the chronic gastric inflammation, partially due to H. pylori infection

These are mostly benign, with only a small risk of dysplasia

Most common non-neoplastic polyp

Question 4

What are these? Describe them

Answer 4

Fundic gland gastric polyps, commonly found in the more proximal (body or fundus) stomach that are usually small (less than 1 cm(, cystic appearing, and clustered on a background of normal, not inflammed stomach

Question 5

What causes most fundic gland gastric polyps?

Answer 5

These may be sporadic, associated with PPI use, or associated with FAP and rarely have malignant potential unless associated with FAP

Question 6

Describe gastric adenomas

Answer 6

These are mostly found in the antrum of the stomach and Almost always occur on a background of chronic gastritis with atrophy and intestinal metaplasia.

They are composed of intestinal-type columnar epithelium that exhibits varying degrees of dysplasia, and the risk of malignancy increases with size, villous lesions, and/or high grade dysplasia

Question 7

T or F. Gastric adenomas are pre-malignant neoplastic lesions with a high risk of transformation to invasive cancer

Answer 7

T. •Like fundic gland polyps, the incidence of adenomas is increased in individuals with FAP.

These need to be removed endoscopically

Question 8

Question 9

What pt. pop gets gastric cancer?

Answer 9

More common in lower SC groups and in developing countries with a 2:1 male predominance and an average onset of around 70 yo

NOTE: There is declining incidence in US of distal gastric cancers except in Caucasiasn aged 29-39

Question 10

What are the main risk factors for gastric cancer?

Answer 10

• Chronic atrophic gastritis
• Pernicious anemia b/c of change in pH
• Prior gastric surgery b/c of change in pH
• High dietary nitrates
• Adenomatous gastric polyps (precursor)
• Smoking and obesity
• Family history gastric cancer-<10 % (Diffuse type)
• Helicobacter pylori infection (Increases risk 3-6 times)

Question 11

Nitrite is a carcinogen

Question 12

Notice the continuing trends of decreased incidence of gastric cancer. What are some main reasons why?

Answer 12

1) Tx H. pylori
2) Refrigeration and decreased meat curing/smoking of meat
3) Increase consumption of vegetables

Question 13

What are some common symptoms associated with gastric cancer?

Answer 13

• diaphragmatic invasions can lead to chronic hiccups
• early perineural invasion can lead to dull pain
• adjacent tissue infiltration can lead to decreased gastric compliance causing early satiety and contributing to weight loss
• Gastric outlet obstruction-distal lesions may obstruct stomach outlet- these will vomit 2-3 hrs after eating
• Ulceration may lead to anemia or hematoemeis and/or melena

Question 14

Answer 14

Endoscopy is the main way to diagnose. Biopsy needed for distinction between ulcer and malignancy. 6-8 biopsies taken usually

Question 15

Question 16

What are the main types of gastric cancer?

Answer 16

90% adenocarcinoma (two types: intestinal and diffuse)

3% lymphoma

0.2% carcinoid

GI stromal tumor (GIST)

Question 17

What pts is the intestinal type of gastric adenocarcinoma more common in?

Answer 17

males and at older ages

Question 18

What pts is the diffuse type of gastric adenocarcinoma more common in?

Answer 18

little difference between sexes and more frequent at younger ages

Diffuse may be familial

Question 19

Question 20

What is this?

Answer 20

Linitis plastica- a very aggressive diffuse type adenocarcinoma representing around 5% of gastric cancers and marked by transmural infiltration of the gastric wall (poor prognosis) resulting in a rigid, leather-bottle, thickened stomach

Question 21

Question 22

Where does gastric cancer usualy MET to?

Answer 22

liver, peritoneum, or distal lymph nodes such as:

left supraclavicular node (aka Virchow’s node)

periumbilical nodule (aka Sister Mary Joseph node)

Question 23

Staging of gastric cancer is based on what?

Answer 23

depth of infitlration into the gastric wall

NOTE: Even early lesions only carry a 5yr survival of 70%- much worse prognosis than colon cancer

Question 24

Answer 24

A. Weight loss and anemia suggest cancer

Question 25

B. More likely to be an adenocarcinoma (lymphoma actually has a better prognosis than adenocarcinoma)

Answer 25

A.

Question 26

Question 27

What is this?

Answer 27

A hyperplastic gastric polyp ## Footnote Micro: Dilated, elongated and tortuous gastric foveolar epithelium with edematous lamina propria containing inflammatory cells

Question 28

What are these?

Answer 28

Fundic gland gastric polyps Micro: Cystically dilated lined by flattened parietal and chief cells

Question 29

How does gastric cancer form?

Answer 29

It is multifactorial with interplay of host and environmental factors. Intially the normal gastric mucosa is subjected to host gene polymorphisms or H. pylori infection which promotes a superficial gastritis, and eventually chronic gastric inflammation exacerbated by a high salt diet or smoking, as well as ROS generation.Chronic inflammation gives rise to atrophic gastritis and eventually metaplasia and dysplasia leading to carcinoma

Question 30

Question 31

Adenoma= low grade dysplasia (left) Right= high grade

Question 32

What kind of gastric adenocarcinoma is this?

Answer 32

Intestinal type, which tends to form bulky antral (along lesser curvature) masses

Question 33

What kind of gastric adenocarcinoma is this?

Answer 33

diffuse types, which infiltrates the wall diffusely, **thickens it**, and is typically composed of **signet ring cells**

Question 34

Familial diffuse gastric cancer is strongly associated with germline loss-of-function mutations in the tumor suppressor gene \_\_\_\_, which encodes the cell adhesion protein **E-cadherin**.

Answer 34

CDH1. 10% of gastric carcinomas are caused by hereditary factors –E-cadherin

Question 35

Individuals with _____ mutations are at increased risk of developing diffuse gastric cancer.

Answer 35

BRCA2

Question 36

What is this?

Answer 36

When there are large areas of infiltration involved with a diffuse gastric adenocarcinoma, diffuse rugal flattening and a rigid, thickened wall may impart a **leather bottle appearance termed linitis plastica**

Question 37

C. B would be a mutation in VHL

Question 38

What kind of gastric cancer is this?

Answer 38

Sporadic type

Question 39

Sporadic type gastric cancer is associated with what mutations?

Answer 39

These include loss-of-function mutations in the adenomatous polyposis coli (**APC**) tumor suppressor gene and **gain-of-function** mutations in the gene encoding **β-catenin** (Increased signaling via the Wnt pathway) Sporadic types are associated with **APC, K-RAS and Tp53 alterations (AK-53)** NOTE: FAP patients, who carry germline APC mutations, have an increased risk of intestinal-type gastric cancer.

Question 40

Left: intestinal type gastric carcinoma

Answer 40

Higher-magnification

Question 41

Answer 41

B. Seeing goblet cells

Question 42