GIT neoplasia patho

Question 1

what is a polyp

Answer 1

a fleshy protuberant growth on an epithelial surface

*some benign polyps are precancerous

Question 2

difference between pedunculated and sessile polyps

Answer 2

• pedunculated - presence of stalk holding polyps
• sessile - no stalk

Question 3

benign polyps

Answer 3

• fundic gland polyps
• hyperplastic polyps

Question 4

what are fundic gland polyps caused by

Answer 4

• sporadic -> eg due to PPI inhibitor reactions/ stress
• familial -> eg FAP

*associated with reduced acidity in stomach

Question 5

what does hyperplastic polyps usually precede

Answer 5

• chronic erosive gastritis

Question 6

what are hyperplastic polyps indicative of

Answer 6

• regenerative response to injury

Question 7

presentation of hyperplastic polyps

Answer 7

• surface erosions leading to bleeding
• multiple polyps present in gastric atrophy

Question 8

malignant stomach carcinomas

Answer 8

• gastric carcinoma
• gastric adenocarcinoma

Question 9

what is gastric adenocarcinoma

Answer 9

• malignant neoplasm showing GI
  glandular epithelial differentiation

Question 10

is gastric carcinoma symptomatic in early stages?

Answer 10

NO

*most pts are not scoped in time to discover carcinoma

Question 11

clinical presentation of gastric carcinoma

Answer 11

• weight loss (due to VOMITING)
• abdominal pain
• dysphagia
• haemorrhage (vomit blood)

Question 12

what is early gastric cancer (EGC)

Answer 12

• invasive cancer (gastric carcinoma) that invades no deeper than submucosa
  *irrespective of lymph node metastasis

Question 13

what is gastric carcinoma associated with

Answer 13

• asians
• JAPAN

*thus japan has mass endoscopy screening to identify gastric cancer at EGC rather than progressing to late stage gastric carcinoma

Question 14

how to describe gastric carcinoma

Answer 14

Exophytic
- protrusion of tumour mass into lumen (ie small bump)
- early exophytic tumour does not erode submucosa, late tumour will erode into submucosa and even into smooth muscle

Flat/ depressed
- no obvious tumour mass within mucosa
- early flat tumour does not erode submucosa, late tumour will erode into submucosa and even into smooth muscle

Excavated
- shallow/ deeply erosive crater present in walls of stomach
- early vs late excavated tumour differs in submucosal vs submucosal + muscle erosion as well

Question 15

types of gastric adenocarcinoma (2)

Answer 15

• intestinal type adenocarcinoma (MAJORITY)
• diffuse type adenocarcinoma

Question 16

describe intestinal type adenocarcinoma

Answer 16

• arise from complete-type intestinal metaplasia
• genetic alterations resemble colonic carcinoma

Question 17

describe diffuse type adenocarcinoma

Answer 17

• arise from gastric foveolar epithelium

presentation:
- broad region of gastric wall extensively infiltrated by malignancy -> create RIGID, THICKENED “leather bottle” termed linitis plastica

Question 18

growth and spread of gastric carcinomas

Answer 18

local infiltrations:
- pylorus and antrum > cardia lesser curve > greater curvature

metastasis
- distant metastases to adrenal gland, peritoneum, ovary, spleen
- metastases to SUPRACLAVICULAR NODES (VIRCHOW’S NODE)

Question 19

intestinal adenomas definition and types

Answer 19

• benign epithelial neoplastic polyps composed of proliferating neoplastic GLANDS

types (different growth patterns)
- tubular adenoma
- tubulovillous adenoma
- villous adenoma

Question 20

what is Peutz-Jeghers Syndrome associated with

Answer 20

• POLYPS (HAMARTOMATOUS) in GI tract
• increased PIGMENTATION around lips, genitalia, feet & hands
• YOUNG CHILDREN
• little malignant potential
• GENETIC related

Question 21

colorectal cancer (malignant) imaging

Answer 21

• polypoidal, ulcerated appearance
• CIRCUMFERENTIAL growth (grows around entire circumference of colon -> constricts colon lumen greatly -> aka APPLE CORE lesions

Question 22

colorectal cancer presentation

Answer 22

• abdominal pain due to intestinal obstruction
• UNEXPLAINED ANEMIA
• spurious diarrhea (alternate diarrhea & constipation due to mucus accumulation and seeping through thin lumen [diarrhea] and faecal obstruction from thin lumen [constipation]
• pneumaturia (gas in urine) due to bladder invasion

Question 23

colon adenocarcinoma epidemiology

Answer 23

• cancer begins in the cells of colonic crypts and spreads first through the wall of the colon and potentially into the lymphatic system and other organs

Question 24

what causes colorectal cancer

Answer 24

• stems from colon polyps that turn cancerous
• individuals that develop multiple polyps -> higher risk of colon cancer

Question 25

hereditary causes of colorectal cancer

Answer 25

• lynch syndrome
• classic FAP (younget age of cancer onset)
• attenuated FAP

Question 26

what is FAP caused by

Answer 26

• autosomal dominant inherited syndrome
• inactivating mutation in APC gene chromosome 5q21 -> disrupt function of tumour suppressor gene at birth -> cancer

Question 27

what are carcinoids

Answer 27

• neuroendocrine tumours

Question 28

effects of carcinoid metastases

Answer 28

• carcinoid syndrome (from over production of substances like serotonin

Question 29

most frequent sarcoma of GI tract

Answer 29

• GIST (gastrointestinal stromal tumour)

Question 30

gastrointestinal stromal tumour (GIST) presentations

Answer 30

• polypoidal intramural tumour masses, ulcerate overlying GI mucosa
• rare: separate masses within mesentery

Question 31

markers used for GIST diagnosis

Answer 31

• CD117
• CD34