Tumors of the Small and Large Bowel Flashcards Preview

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Flashcards in Tumors of the Small and Large Bowel Deck (46):
1

What are risk factors for SI adenocarcinoma?

Crohn's disease
adenomas
celiac disease

2

What is GIST?

gastrointestinal stromal tumor
most common non-epithelial/soft tissue tumor in GI tract
derived from pacemaker cells (interstitial cells of cajal)

3

What is useful for treatmetn of GIST?

imatinib

4

What are the markers of GIST?

CD117 (c-kit)
DOG1
CD34

5

Describe carcinoid syndrome

vasomotor disturbances, intestinal hypermotility, wheezing, hepatomegaly, cardiac involvement
(increased serotonin)

6

Define non-neoplastic polyp

result of abnormal mucosal maturation, inflammation, distorted architecture
no malignant potential

7

Describe neoplastic polyp

arise as a result of proliferatio nnad dysplasia (adenomas)
precursor of carcinoma

8

What are the types of non-neoplastic polyps?

hamartomatous
inflammatory
lymphoid

9

What is a hamartoma?

benign w/no malig pot
composed of mature, histologically normal elements from that site growing in a disorganized manner

10

What are different types of hamatomatous polyps?

juvenile polyps
peutz jeghers polyps
cowden syndrome
cronkhite-canada

11

Features of juvenile polyps?

kids <5
80% in rectum
pedunculated
expanded lamina propria
hamartomatous
non-neoplastic

12

What genes are associated with juvenile polyposis syndrome? other features?

SMAD4, BMPR1A
increased risk of adenomas
10-50% risk of colon cancer
multiple juvenile polyps

13

What is peutz jeghers syndrome?

AD STK11
mutliple GI polyps
hyperigmentation of the mouth and fingers
increased risk of intussusception
increased risk of cancer of the pancreas, breast, lung, ovary, uterus
large and pedunculated, lots of goblet cells

14

What is cowden syndrome?

AD
hamartomatous GI polyps
facial trichilemmomas, oral papillomas, acral keratoses
assoc risk of thyroid and breast cancer
polyps themselves no malig pot

15

What is cronkhite-canada?

non hereditary
GI hamartomatous polyps
ectodermal abnormalities (nail atrophy, alopecia)

16

What are inflammatory polyps?

pseudopolyps-regenerating mucosa adjacent to ulceration (seen in severe IBD)

17

What are lymphoid polyps?

mucosal bumps caused by intramucosal lymphoid follicles-normal

18

What are serrated polyps?

smooth protrusions of mucosa usally at the top of mucosal fold
serrated lamina nad increased numbers of goblet cells
hyperpastic or sessile

19

Which type of serrated polyp has malignant potential?

sessile serrated
BRAF V600E mutations

20

What are adenomatous polyps? (adenomas)

Arise as a result of epithelial proliferative dysplasia
precursor lesions for adenocarcinoma
-tubular, villous, and tubulovillous adenoma
fourfold greater risk of developing adenomas among 1st deree relatives of pts w/ & risk of developing carcinoma

21

Where are most tubular adenomas found?

colon

22

What are villous adenomas?

villous projection
often large, sessile
older ppl in rectosigmoid
cancer invasion directly into colon wall

23

What is the only adequate treatment for an adenoma?

complete resection

24

What is the most common colorectal cancer?

adenocarcinoma
-usually in rectosigmoid

25

What are risk factors for colorectal cancer?

diet
obesity/inactivity
geography?

26

What is right sided colon cancer usually like?

non obstructive
fatique, weakness, iron deficiency anemia
polypoid eophytic lesions

27

What is left sided colon cancer usually like?

may be obstructive
occult bleeding, changes in bowel habit, abd discomfort
annular napkin ring constrictions
tend to be more infiltrative

28

What gene(s) are often inactived in adenoma carcinoma pathway?

inactivated APC
if not inactivated APC B-catenin mutations
(leads to increased WNT signaling, decreased cell adhesion and increased cellular proliferation)
loss of p53 late

29

What is the depth of invasion for TIS-T4

TIS carcinoma in situ
T1 submucosa
T2 muscularis propria
T3 serosa
T4 other organs/structures

30

What is the most important prognostic indicator of colorectal carcinoma?

Stage=T + M + N

31

Where does colon cancer like to spread?

lymph nodes, liver, lungs, bones

32

What is the major negative predictor of efficacy in EGFR moAB therapy?

KRAS mutation
BRAF mutation correlates with poor prognosis and lack of response

33

Describe FAP

AD mutation of APC gene
>100 colonic adenomas
colon adenocarcinoma 100% of the time
prophylactic colectomy

34

What is gardner's syndrome?

FAP variant
adenomatous polyposis with osteomas, epidermoid cysts, desmoid tumros

35

What is turcot syndrome?

FAP variant
adenomatous polyposis with medulloblastoma

36

What is MAP?

aka MYH associated polyposis
hereditary colorectal cancer syndrome that has phenotypic overlap w/FAP
20-100 adenomatous polyps usually
AR
due to mutations in MYH gene
presents older than FAP

37

What does MYH protein do?

DNA repair protein-base excision repair
repairs oxidation induced DNA damage by removing A mis-paired with G

38

What is lynch syndrome?

increased risk of colorectal & endometrial cancer in females (also SI, ureter, renal pelvis)
adenomas earlier than normal pop but in low nubers
microsatellite instability pathway, DNA mismatch repair genes busted

39

What is Muir Torre syndrome?

a lynch syndrome variant
associated wtih multiple sebaceaous adenomas, sebaceous carcinomas, and keratoacanthomas

40

What does microsatellite instability lead to?

accumulation of mutations in the genome

41

What do microsatellites serve as sensitve markers of?

mistmatch repair function
-typically microsatellites are shorter in tumor tissue

42

Is braf mutation seen in lynch syndrome?

No! never

43

What are the 2 main types of anal canal carcinoma?

basaloid differentiation
squamous cell

44

What is the most common tumor of the appendx?

carcinoid

45

What is a mucinous cystadenoma/cystadenocarcinoma?

a mucous secreting epithelial tumor
creates mucoceles

46

What is pseudomyxoma peritonei?

"jelly belly"
mucin from mucinous cystadenoma/cystadenocarcinoma leaks into the peritoneal cavity and encases organs