Intestine Path 2 Flashcards Preview

Block 7 - GI > Intestine Path 2 > Flashcards

Flashcards in Intestine Path 2 Deck (29):
1

What causes Crohn dz?

environmental, immunological and bacterial factors interact and result in chronic inflammatory disorder where immune system attacks GI tract in absence of any invader

2

What genetic factors may play a role in Crohn?

NOD2 gene
HLA-DQ4 and HLA-DR7

3

What cells may be implicated in the pathology of Crohn dz?

Th17 cells

4

What are symptoms of Crohn dz?

ab pain, diarrhea (maybe blood), malabsorption and weight loss, perianal itching, pain or bleeding

5

What are the complications of Crohn dz?

strictures, obstruction, fistulae, adhesions, abscesses

6

What are extraintestinal manifestations of Crohn dz and ulcerative colitis?

erythema nodosum and pyoderma gangrenosum
uveitis, episcleritis
inflammatory seronegative arthropathies
hepatitis, PSC, coagulopathies
hydronephrosis
prothrombotic tendency in veins
ostopenia in Crohns

7

What are characteristics of Crohn dz?

skip lesions, fat wrapping, cobblestoning, apthous ulcers, non-caseating granulomas, lymphoid beads, pyloric metaplasia, thickened fibrotic wall (look for sticks!), transmural inflammation and fissures

8

What is the treatment of Crohn dz?

antibiotics, 5-ASA, prednisone and immunomodulators
avoid surgical resection, not cured by surgery

9

What are the complications of ulcerative colitis?

iron deficiency anemia
blood loss requiring transfusion
toxic megacolon
dysplagia and adenocarcinoma

10

What are characteristics of ulcerative colitis?

friability and bleeding, pseudopolyps, loss of haustral folds, continuous distribution, shortening of colon, chronic inflammation of MUCOSA, no fibrosis or granulomas, collar button ulcers, gland dropout

11

What cell feature indicates high grade dysplasia in ulcerative colitis?

nuclei in upper half of cells

12

What are hyperplastic polyps?

small <5mm, non-neoplastic
rectosigmoid
smooth surfaced

13

What is the histology of hyperplastic polyps?

abundant crypts lined by mucinous goblet cells, star-like patterns to crypts, scant intervening lamina propria, no dysplasia

14

What are characteristics of adenomas (neoplastic polyps)?

sessile or pedunculated
tubular, tubulovillous, villous

15

What three features of adenomas correlate with risk of malignancy?

SIZE
architecture
degree of dysplasia

16

What do adenomas look like histologically?

bluer - mucin depletion/loss of goblet cells, nuclear hyperchromasia, piling of nuclei, mitoses

17

What is a sign that a high grade dysplasia is NOT at risk for being malignant?

doesn't go past muscularis mucosa into submucosa - no lymphatic channels

18

What is FAP?

AD from APC gene ch 5q21, 100% risk of CRC

19

What are complications from the sheer number of polyps in FAP?

intussusception, obstruction, bleeding, rectal prolapse

20

What is HNPCC (Lynch syndrome)?

polyps - not as many as FAP
DNA mismatch repair gene mutation results in microsattelite instability
MMR mutation

21

What are the precursor lesions of Lynch?

sessile serrated adenomas, large right sided hyperplastic polyps, mucinous carcinomas (uterine/ovarian)

22

What diets are associated with CRC?

high in fat and low in fiber

23

What can have a protective effect against CRC?

aspirin and other NSAIDs

24

What are the two pathways for the dev of colon cancer?

APC/beta catenin pathway
DNA mismatch repair

25

What events constitute the APC/beta catenin pathway?

first - APC gene
remaining hits could be - K-ras mutations, p53 mutation, DPC4/DCC/SMAD4 mutation, EGFR, DCC

26

What are characteristics of right sided CRCs?

exophytic, obstruction is uncommon since ascending is wider --> iron deficiency anemia, SOB

27

What are characteristics of left sided CRCs?

outward into lumen, obstructs feces, napkin ring constriction or apple core lesion --> change in bowel habits, positive stool Guaiac test

28

What are microscopic features of CRC?

cribiforming (multiple lumens)
sometimes mucinous (colloid)
signet ring cells
geographic necrosis

29

What is the role of CEA in CRC?

not useful for screening
high rates correlate w adverse prognosis
serial measures can detect recurrence
good at detecting liver metastases from CRC