GIT 4

Question 1

contains star shaped glands < 5mm
recto sigmoid colon
no malignant potential

Answer 1

hyperplastic polyp

Question 2

haphazard tissue 
prolapsed mass from childs butt 
< 5 yo 
retention polyps contained of cystically dilated glands 
MC rectum 
spontaneous removal with stools

Answer 2

juvenile polyps

Question 3

looks like tree
musclularis mucosa - arborizing gland
small intestine

assoc: polyp + multiple other carcinomas + hyperpigment in mouth, lips, and skin like freckles

Answer 3

peutz jeghers polyps

Question 4

pedunculated
small intestine, stomach, ampulla of vater
benign - cancer rare

long standing constipation, rectal occult, bleeding IDA

Answer 4

tubular adenoma

Question 5

large sessile
rectum/rectosigmoid
villous projection
40% chance of cancer
dysplasia 

long standing constipation, rectal occult, bleeding IDA

Answer 5

villous/ serrated adenoma

Question 6

adenoma mutations

Answer 6

normal colon > mut MLH1/MSH2 > sessile polyp (micro satellite = DNA repair defect) > mut BAX and BRAF > carcinoma

Question 7

> 100 polyps
mut APC (5q21) - tumor supressor gene
negative regulator of WNT pathway
AD

Answer 7

FAP

Question 8

exhibit intestinal polyps identical to those in classic FAP - osteoma, epidermal cysts, fibromatosis, CA breast

Answer 8

variant FAP = gardener syndrome

Question 9

AD
defects in mismatch DNA repair genes - MLH1 MSH2 > leading micro satellite instability

r colon cancer, endometrial cancer ovarian cancer

Answer 9

Lynch syndrome = HNPCC

Question 10

combination

subjects with multiple adenomas or an FAP phenotype without APC mutations

Answer 10

MYH associated polyps

Question 11

adenoma carcinoma seq - multistep carcinogenesis = 7 total mutations

Answer 11

normal colon (mut APC; 1st hit; 5q21) > mucosa at risk (mut APC; beta catenin; 2nd hit; no polyps) > immature polyp (KRAS mut 12p12) > fully developed polyps (over expression COX2; decrease p53 17p13; SMAD 2 and 4) > carcinoma (telomerase)

Question 12

polypoid exophytic masses
obstruction is uncommon
IDA
spherical tumor
DNA repair defect - HNPCC

Answer 12

proximal colon - right

Question 13

annular, encircling lesions (napkin ring constructions)
stays in wall making lumen narrow
early obstruction is common 
no anemia - only later - IDA
causes: APC, UC, food habits

Answer 13

distal colon - left

Question 14

CEA used for

Answer 14

monitoring recurrence

Question 15

SCC
below the and rectal junction
due to chronic HPV

Answer 15

ano rectal cancer

Question 16

carcinoid tumors derived from

Answer 16

neuroendocrine tumors

Question 17

MC appendiceal
elevated 5HIAA
salt and pepper on micro

form discrete islands, trabelculae, strands, glands, organoid

on EM: dense core granular filled with hormone; stipples nuclei

Answer 17

carcinoid syndrome

Question 18

serotonin excess 
mets in liver
flushing 
diarrhea
asthma 
tricuspid problems

Answer 18

carcinoid syndrome

Question 19

increase gastrin

multiple non healing ulcers

Answer 19

gastrinoma

Question 20

increase ACTH

HTN, weight gain, moon face

Answer 20

Cushings syndrome

Question 21

obstruction

appendicitis - RLQ pain and neutrophils

Answer 21

appendix carcinoid

Question 22

assoc with MALToma

Answer 22

chronic gastritis: H pylori
chronic sprue
natives of Mediterranean
inf in HIV

Question 23

spindle cells
C KIT
CD117

Answer 23

GIST

Question 24

caused by heavy use of laxatives

enterocytes become smaller due to autophagy - eating of cell membrane > deposit lipofusion > brown/black pigmented colon

C/F: constipation; can mimic tumor

Answer 24

melanosis coli

stain oil o red