Colon

Question 1

What percent of the lamina propria is inflammatory cells in normal colonic mucosa?

Answer 1

50%

Question 2

T/F- water must cross the surface epithelium and collagen table to enter the capillaries of the superficial lamina propria

Answer 2

true

Question 3

Hirschsprung disease is associated with what genetic abnormality?

Answer 3

Down syndrome

Question 4

T/F- Although males get hirschsprung disease more frequently than females, females are more severely affected

Answer 4

true

Question 5

A neonate presents with failure to pass meconium in the immediate postnatal period. What is most likely diagnosis?

Answer 5

Hirschsprung disease

Question 6

Name 5 common causes of acute colitis

Answer 6

Bacterial
viral (norovirus, rotavirus, adenovirus)
Protozoal and parasitic
Toxin
Ischemic

Question 7

Name 4 causes of chronic colitis

Answer 7

Ulcerative colitis, Crohn’s disease

Lyphocytic colitis, collagenous colitis

Question 8

T/F- crypt architecture is not preserved in acute bacterial colitis

Answer 8

False, it is preserved

Question 9

Name 2 examples of toxin damage causing colitis

Answer 9

1. C. dificile (pseudomembranous colitis), most commonly after 3rd gen cephalosporin
2. Enterohemorrhagic E. Coli (fecal contamination, raw hamburger, sprouts, apples picked in pasture)

Question 10

What is the pseudomembrane composed of?

Answer 10

fibrin, mucin, neutrophils

Question 11

ichemic colitis most often occurs in older patients with vascular disease and presents with abdominal pain, nausea, vomiting, bloody stools. Where are the watershed zones where this most often occurs?

Answer 11

splenic flexure, sigmoid colon, rectum

Question 12

T/F- Irritable bowel syndrome will show gross and microscopic abnormalities

Answer 12

False, it will be normal

Question 13

In chronic colitis, is crypt architecture and branching preserved or distorted?

Answer 13

distorted and irregular crypts are signs of chronicity

Question 14

Compare ulcerative colitis and Crohns disease

Answer 14

• UC: diffuse, superficial (only mucosal layer affected), colon only
• Crohns: focal (lymphoid aggregates or granulomas), transmural (mucosa through to serosa), anywhere in the GI tract (especially ileum and colon)

Question 15

If you see a terminal ileum with a thick wall, stricture, and linear ulcer what is it most likely?

Answer 15

Crohn’s disease

Question 16

Does Crohn’s or ulcerative colitis carry a greater risk for cancer?

Answer 16

Ulcerative colitis

Question 17

The term microscopic colitis encompasses what two diseases?

Answer 17

• Lymphocytic and collagenous colitis

- these will appear normal endoscopically

Question 18

T/F- in collagenous colitis you will see microscopically normal crypt architecture, increased superficial chronic inflammation of the lamina propria, increased numbers of intraepithelial lymphocytes

Answer 18

False, that is lymphocytic colitis

Question 19

What will you see histologically in collagenous colitis?

Answer 19

A thickened, irregular subepithelial collagen layer entrapping capillaries and cells

Question 20

Is diverticulosis related to the western diet?

Answer 20

yes

Question 21

Although only 20% of patients are symptomatic for diverticulosis, what will they present with?

Answer 21

cramping, lower abdominal discomfort, constipation/diarrhea, distention

Question 22

Where is the weakest spot in the muscle that allows for diverticuli to form?

Answer 22

where
nerves and vessels
penetrate

Question 23

Can diverticulitis perforate?

Answer 23

yes

Question 24

T/F- Inflammatory polyps are often associated with IBD, but also seen with ischemic colitis, infectious colitis, necrotizing enterocolitis

Answer 24

true

Question 25

Juvenile polyps often present with rectal bleeding or prolapse of polyp through the rectum. Does polyposis syndrome increase risk of malignancy?

Answer 25

risk of upper and lower GI malignancies

Question 26

For Peutz-Jeghers syndrome, what is the mode of inheritance? Symptoms? Complications?

Answer 26

- Autosomal dominant - Mucocutaneous pigmentation - polyps of the upper and lower GI tract with increased risk of carcinoma, pancreatic, breast, and ovarian carcinomas

Question 27

Hyperplastic polyps are commonly found where? Are they malignant or benign?

Answer 27

- Left colon and rectum | - Benign

Question 28

Do sessile, serrated adenomas/polyps have malignant potential? Where are they commonly found?

Answer 28

yes, most often on right side of colon

Question 29

How do you distinguish a sessile serrated adenoma from a hyper plastic polyp?

Answer 29

Sessile serrated adenoma has normal base, hyper plastic polyp has abnormal base

Question 30

Name three different types of adenomas

Answer 30

1. tubular 2. tubulovillous 3. villous

Question 31

Are adenomas a precursor to colon cancer?

Answer 31

yes "These are the MAJOR precursor to colon cancer"

Question 32

Once an adenoma passes ______ layer it becomes invasive

Answer 32

muscularis mucosae

Question 33

T/F- adenocarcinoma is rare in western populations

Answer 33

False, VERY common in western populations and account for 3% of cancer deaths

Question 34

Are adenocarcinomas related to dietary factors?

Answer 34

yes, low intake of vegetable fiber and high intake of refined carbohydrates and fat

Question 35

Is the preclinical phase of colorectal cancer long or short?

Answer 35

long (10 years)

Question 36

What lesion do the vast majority of colorectal cancers begin with?

Answer 36

tubular adenoma

Question 37

T/F- The majority of colorectal adenocarcinomas are associated with familial syndromes such as FAP, HNPCC, juvenile polyposis coli

Answer 37

``` False, 90% are sporadic! FAP: 1% HNPCC: 5% Juvenile Polyposis coli: 1% IBD: 1% ```

Question 38

Familial adenomatous polyposis is an autosomal dominant mutation in what gene?

Answer 38

APC (adenomatous polyposis coli) gene

Question 39

How many adenomas would you find in a colon of a person with FAP?

Answer 39

at least 100, often more than 1000

Question 40

T/F- colorectal adenocarcinoma will develop in 100% of untreated FAP patients

Answer 40

true

Question 41

HNPCC includes lynch syndrome I and II, what is the difference?

Answer 41

-Lynch Syndrome I – confined to colorectum -Lynch syndrome II – colorectal carcinoma associated with extra-colonic cancers (Endometrium, stomach, small bowel, hepatobiliary tract, pancreas, ovary, urinary tract, brain (GBM), sebaceous neoplasms of the skin (Muir-Torre syndrome))

Question 42

Is HNPCC autosomal dominant or recessive? What type of gene does this affect?

Answer 42

dominant | DNA mismatch repair gene (risk of colorectal cancer is 70% by age 70)