Large intestines II

Question 1

What is the most common type of adenomatous polyps?

Answer 1

Tubular adenoma

Question 2

What percent of polyps are villous adenomas? Who are these found in?

Answer 2

1% Older people

Question 3

How big can villous adenomas get before they’re considered CA?

Answer 3

4 cm

Question 4

Is there a stalk with villous adenomas?

Answer 4

no

Question 5

What are the histological characteristics of villous adenomas?

Answer 5

Finger like projections

Question 6

What are tubulovillous adenomas? The risk of CA with these is proportional to what?

Answer 6

Adenomas with partial stalk and part villous architecture. CA risk correlates with villous proportion

Question 7

What are the three factors that predict whether or not a polyp will develop into CA?

Answer 7

Size (max diameter is chief determinant)
Proportion of villous component
Degree of dysplastic change

Question 8

What are the clinical ssx of adenomas?

Answer 8

asymptomatic to bleeding

Question 9

When can adenomas metastasize?

Answer 9

if they cross the muscularis mucosa

Question 10

What are the three histological considerations for excising an adenoma?

Answer 10

1. Adenocarcinoma is superficial
2. No vascular or lymphatic invasion
   3 CA is not poorly differentiated

Question 11

What is the only treatment for adenomas?

Answer 11

Complete resection

Question 12

Why are villous adenomas more worrisome for CA?

Answer 12

closer to BM

Question 13

What is the adenoma-carcinoma sequence?

Answer 13

Theory that CA develops from adenomatous lesions based on observations and evidence of genetic alterations

Question 14

How does the distribution of adenomas and adenocarcinomas relate?

Answer 14

Very similar distribution

Question 15

True or false: cancer risk is directly related to the number of adenomas?

Answer 15

True

Question 16

True or false: the incidence of colorectal CA decreases if adenomas are removed?

Answer 16

True

Question 17

True or false: most GI cancers arise sporadically

Answer 17

True

Question 18

What is the age range for the development of rectal CA?

Answer 18

60-70

Question 19

True or false: ASA and other NSAID use may increase the risk of developing GI CA

Answer 19

False–protective

Question 20

Fe deficiency anemia in an older male means it is what until proven otherwise?

Answer 20

GI tract CA

Question 21

Where does most of the GI tract drain lymph to?

Answer 21

Liver

Question 22

What is the pattern of inheritance for familial adenomatous polyposis?

Answer 22

AD

Question 23

What is familial adenomatous polyposis?

Answer 23

mutation of the APD gene, a tumor suppressor gene, which regulates the WNT pathway

Question 24

Describe the role of FAP in the WNT pathway.

Answer 24

Absence of the APC gene in the WNT pathway inhibits the destruction of beta-catenin. This can then go into the nucleus of a cell, and transcribe myc and Cyclin D

Question 25

What is the cause of HNPCC (lynch syndrome)?

Answer 25

Defects in the pathway of DNA mismatch repair, specifically MSH2 or MLH1. MSH2 identifies mismatched DNA MLH1 repairs them

Question 26

Why is the APC gene mutation so concerning?

Answer 26

WILL cause carcinoma of the GI tract

Question 27

What is the attenuated FAP?

Answer 27

APC and MUTYH mutations cause a less severe type of polyposis

Question 28

What is Gardener's syndrome?

Answer 28

Polyposis syndrome that can result in tumors outside the GI tract. Caused by a mutation in the APC gene.

Question 29

What is Turcot syndrome?

Answer 29

APC gene mutation that causes polyposis with medulloblastomas

Question 30

What is the model of the genetic alterations needed for HNPCC to develop?

Answer 30

APC or MSH2 are mutated on BOTH alleles (two hit phenomenon), causing a loss of DNA mismatch repair and more mutations, leading to CA

Question 31

Why are right sided polypoid masses rarely obstructive?

Answer 31

stool is still watery at this pint

Question 32

Pencil thin stool are suspicious for what?

Answer 32

Annular, encircling lesions in the left colon

Question 33

Mucin production is a good or bad sign of colorectal CA?

Answer 33

Bad

Question 34

What are carcinoid tumors?

Answer 34

Carcinoid tumors are a type of neuroendocrine tumor, which means they come from cells of the nervous and endocrine system, and can produce hormones. When they secrete excess hormones such as histamine and serotonin, they can cause symptoms such as flushing, stomach cramps, and diarrhea.

Question 35

Which location of carcinoid tumor rarely metastasizes? Which often does?

Answer 35

Appendix = rare | Ileal, gastric, colonic - frequent

Question 36

What is the cause of carcinoid syndrome?

Answer 36

Mets of carcinoid tumors to the liver. These release 5HT and cause flushing/diarrhea/wheezing

Question 37

What are the gross characteristics of carcinoid tumors? Histological?

Answer 37

Yellow, firm tumors Minimal atypia, monotonous, uniform cells

Question 38

Who gets carcinoid tumors?

Answer 38

60 yo

Question 39

What types of lymphoma are common in the GI tract (what cell origin)?

Answer 39

B cell origin

Question 40

What percent of gastrointestinal lymphomas are extranodal?

Answer 40

40%

Question 41

What are the three main types of gastric lymphomas?

Answer 41

MALT SPru-associated Mediterranean lymphomas

Question 42

True or false: GI lymphomas are usually inherited

Answer 42

False-- sporadic

Question 43

When are GI lymphomas treated with surgery?

Answer 43

If large enough to cause an obstruction

Question 44

MALT lymphomas have what cellular origin, usually?

Answer 44

B cell

Question 45

MALTomas are usually associated with what infection?

Answer 45

H.Pylori

Question 46

Why are MALTomas different from nodal lymphomas?

Answer 46

Behave as a focal tumor

Question 47

What is the cellular origin of Mediterranean lymphoma? What does this cause?

Answer 47

B cells that produce abnormal IgA heavy chain.

Question 48

WHo gets intestinal T-cell lymphomas?

Answer 48

Pts with celiac sprue

Question 49

True or false: GI lymphomas have a worse prognosis that those arising in other sites

Answer 49

False--better prognosis

Question 50

What are mesenchymal tumors of the GI tract? What is the cause of them?

Answer 50

GISTs that are caused by a somatic mutation in c-KIT gene--a tyrosine kinase receptor

Question 51

What are the histological characteristics of appendicitis?

Answer 51

PMN infiltration

Question 52

What are the three types of appendix tumors?

Answer 52

Mucocele Mucinous cystadenoma Mucinous cystadenocarcinoma

Question 53

What is a mucocele?

Answer 53

Mucinous production--benign

Question 54

What is a mucinous cystadenomas? Mucinous cystadenocarcinoma?

Answer 54

Both are mucin filled spaces and glands. the CA produces pseudomyxoma peritonei (mucus secreting malignant cells in the abdo)