4. Polyps and Masses

Question 1

Gastric Fundic Polyp causes

Hint: Polyp is a growth and what triggers growth

Answer 1

PPI

• low acid, Gastrin, stimulate growth of cells, mucosa
• oxyntic glandular hyperplasia

FAP can also

• APC gene; AD
• controls beta catenin - cell to cell adhesion
• TSG

Question 2

Chronic gastritis polyp Cx

Answer 2

Hyperplastic Polyp

Question 3

Gastric Malignant Cancer morphologies (3)

2 types and features

Answer 3

Adenocarcinoma

• Diffused typed - from foveolar epithelium, individual cells not stuck tgt, SIGNET ring cells - linitis plastica (leather bottle)
• Intestinal type - intestinal metaplasia - MAJORITY
• Exophytic
• Flat
• Excavated

Question 4

What is Early Gastric Cancer

Answer 4

Adenocarcinoma at mucosa only, better prognosis

Question 5

Name [3] Intestinal Adenoma/ Adenomatous Polyp growth patterns and which has highest risk of CC

Answer 5

Tubular, Tubulovillous, Villous
- note greater mutation - less goblet cell production w hyperchromatisim

Villous highest risk of CC

Question 6

Proximal vs Distal Colon growth patterns of AC

Answer 6

Proximal: Exophytic polypoid mass
Distal: Annular, encircling

Question 7

FAP

Answer 7

Inactivating of APC TSG; autosomal dominant

- second hit leads to cancer

Question 8

Tumour Staging of TMN for CC requires…

Answer 8

Breach beyond the muscularis mucosae - MUCOSA, not basement membrane;

Question 9

Carcinoid/ NE Cell tumors presentation

Answer 9

Carcinoid Syndrome - when metastasize

• releases substances including serotonin, vasoactive amines, into systemic circulation
• Bronchoconstriction, Diarrhea, Flushing…
• vasodilation - edema from increased capillary pressure

Question 10

Mass under the muscosa…

Answer 10

Gastrointestinal Stroma Tumors - GIST

Sarcoma of spindled cells

KIT RTK mutation