GI: Small and Large Intestine II

Question 1

What is the infectious disease agent responsible for pseudomembranous colitis?

Answer 1

C. diff (toxins A and B)

Question 2

Which parasitic infection presents with bloody diarrhea?

Answer 2

E. histolytica

Question 3

What is the genetic abnormality in familial adenomatous polyposis (FAP)?

Answer 3

autosomal dominant

mutation of APC gene

Question 4

What are the 2 varieties of GI protrusions?

Answer 4

1) diverticulum

2) hernias

Question 5

What comprises a “true” diverticulum?

Answer 5

all three wall layers (ex: Meckel’s)

Question 6

If the diverticulum only penetrates the mucosa and submucosa, what is it called?

Answer 6

false or pseudo

Question 7

Define diverticulosis

Answer 7

many diverticuli, usually in sigmoid colon where vasa recta perforate colon

(most cases in elderly, associated with low fiber diets)

Question 8

Define diverticulitis

Answer 8

inflammation of diverticula (LLQ pain, fever, leukocytosis) can perforate causing peritonitis, abscesses, etc)

Question 9

Define hernias?

Answer 9

serosal lined out-pouching of peritoneum (loop of intestines are trapped within hernia sac)

bowel compressed and twisted at mouth of hernia

Question 10

What are some causes of ischemic bowel disease?

Answer 10

anything that causes vasculature problems (atherosclerosis, aortic aneurysm, hypercoagulable states, etc)

Question 11

What are some symptoms of ischemic bowel disease?

Answer 11

sudden/severe abdominal pain
tenderness
bloody diarrhea, melanotic stools

Question 12

What is the main watershed zone in the bowel?

Answer 12

splenic flexure (furthest from the blood supply - most vulnerable to ischemia)

Question 13

What does ischemic bowel disease look like on histology?

Answer 13

necrotic mucosa next to intact crypts

Question 14

Internal hemorrhoids are __________ the pectinate lines and are ____________

Answer 14

above

PAINLESS

Question 15

External hemorrhoids are _________ the pectinate line and are ____________

Answer 15

below

PAINFUL

Question 16

True or false: both varieties of hemorrhoids are worse with defecations

Answer 16

TRUE

Question 17

Name the 4 kinds of bowel growths that are NON-neoplastic

Answer 17

1) inflammatory polyp
2) juvenile polyp
3) hamatomaous (psutz-Jeghers syndrome)
4) hyperplastic polyp

Question 18

What are inflammatory polyps and how do they form?

Answer 18

form in the colon due to impaired relaxation of the anorectal sphincter which creates a sharp angle at the anterior rectal shelf (leads to recurrent abrasion and ulceration of the overlying rectal mucosa)

Question 19

How are inflammatory polyps associated with prolapse?

Answer 19

they are pulled by the fecal stream

Question 20

What do inflammatory polyps look like on histology?

Answer 20

lamina propria fibromuscular hyperplasia, inflammation and erosion and epithelial hyperplasia

Question 21

Where do juvenile polyps occur?

Answer 21

rectum in kids

Question 22

Are juvenile polyps concerning?

Answer 22

not if single, if multiple there is an increased risk of adenocarcinoma

Question 23

What is Hamatomatous (Peutz-Jeghers syndrome)?

Answer 23

formation of many hamartomas throughout GI tract (looks like hyperpigmented melanotic macules of mouth, lips, genitalia, hands)

polyps have no malignant potential

Question 24

What are hyperplastic polyps?

Answer 24

look like adenomas, proliferation of mature goblet cells

Question 25

What are adenomatous growths?

Answer 25

benign polyps that are precursors to majority of colorectal adenocarcinomas (can be pedunculated, sessile, tubular, and villous)

Question 26

What are the two major things to monitor in adenomatous growths so that they do not become cancerous?

Answer 26

size and presence of high grade dysplasia

Question 27

Sessile serrated adenomas occur predominantly where?

Answer 27

right colon

Question 28

Define adenomatous dysplasia

Answer 28

neoplastic dysplastic epithelium which lines the glands as tall hypercrhomatic somewhat disordered cells with or without mucin production

Question 29

What is FAP?

Answer 29

an AD disease that leads to thousands of polyps and ALWAYS leads to colorectal adenocarcinoma

Question 30

How do you treat FAP?

Answer 30

prophylactic colectomy

Question 31

What causes FAP?

Answer 31

APC mutations

Question 32

What are 3 neoplastic GI conditions?

Answer 32

1) adenomatous 2) sessile serrated adenoma 3) adenomatous dysplasia

Question 33

What are the 2 variants of FAP?

Answer 33

1) gardner - osteomas of mandible | 2) turcots - DNA repair mutations, get glioblastomas

Question 34

What is HNPCC?

Answer 34

hereditary nonpolyposis colorectal cancer (fewer polyps but cancer still occurs at younger age)

Question 35

What causes HNPCC?

Answer 35

mutation in DNA mismatch repair genes

Question 36

What are the two molecular pathways that can lead to colorectal cancer

Answer 36

1) APC/WNT pathway | 2) DNA mismatch repair

Question 37

True or false: for the APC/WNT pathway, both copies must be functionally inactivated to cause cancer

Answer 37

TRUE

Question 38

What is APC?

Answer 38

a negative regulator of the beta catenin pathway so without APC, beta catenin goes into the nucleus and activates transcription of genes such as those encoding MYC and cyclin D1

Question 39

Which pathway is associated with increased beta catenin?

Answer 39

APC/WNT

Question 40

DNA mismatch repair leads to ________

Answer 40

HNPCC

Question 41

What kind of adenomas are caused by HNPCC?

Answer 41

sessile serrated

Question 42

sporadic colorectal cancer is associated with _______ while sessile serrated adenoma is associated with ________

Answer 42

sporadic CRC --> FAP SSA --> HNPCC

Question 43

What doe colorectal cancer look like on barium xray

Answer 43

apple core (pushes on colon) screen after 50

Question 44

What is partially protective for CRC?

Answer 44

high fiber diet

Question 45

What are some signs and symptoms of right sided CRC?

Answer 45

iron deficient anemia (surface ulceration and blood loss) ulcerate because of fecal matter banging up against it

Question 46

What are some features of left sided CRC?

Answer 46

change in bowel habits, blood in stool, originates from ruptured vessels obstructive, napkin ring

Question 47

____________ kind of cancer develops in the rectum while ____________________ develops in the anus

Answer 47

adenocarcinoma SCC

Question 48

How are GI tumors staged?

Answer 48

based on depth of invasion

Question 49

Name 3 neoplasms of the appendix?

Answer 49

1) mucocele (benign dilatation of lumen by mucinous secretions) 2) mucinous cystadenoma (proliferation of benign neoplastic cells - dilatation by mucinous material) 3) mucinous cystadenocarcinoma (invasion fo neoplastic cells)

Question 50

What does pseudomyxoma peritonei mean?

Answer 50

describes distention of peritoneal cavity by presence of semisolid mucin and epithelial mucin producing implants and/or malignant cells