Pathology of GIT: UC and Crohn's disease

Question 1

Crohn’s disease is thought to go through the ______ pathway and cause the activation of ______ (inflammatory cell) leading to the formation of histolytic components such as granulomas

Answer 1

TNF pathway leading to the activation of macrophages = Crohn’s
(TH1)

Question 2

what IBD is associated with liver abnormalities?

Answer 2

UC because it is associated with primary sclerosing cholangitis (P-ANCA)

Question 3

in addition to necrotizing, large granulomas in TB caused colitis, you will also see longitudinal/transverse (direction) ulcers

Answer 3

transverse; Transverse = Tb

will see longitudinal ulcers in Crohn’s

Question 4

What is the HLA association in Crohn’s disease

Answer 4

HLA DR7 and DQ4

Question 5

what is the HLA association in UC

Answer 5

HLA DRB1

Question 6

OCP’s is a risk factor for which occlusive cause of ischemic bowel disease

Answer 6

venous thrombosis

Question 7

circumferential ulcers are seen in _______ caused colitis

Answer 7

NSAID related colitis

Question 8

_________ is a toxigenic organism that can cause acute ischemic colitis

Answer 8

EHEC/STEC which will have pain, bloody diarrhea and hemolysis and renal failure (HUS)

Question 9

which fluoroquinolone is associated with C. difficile colitis?

Answer 9

ciprofloxacin

Question 10

mucosal and submucosal involvement with

Answer 10

UC; starts at rectum and has diffuse pattern of involvement (NOT FULL THICKNESS)

Question 11

describe the ulcers seen in typhoid (enteric fever) in the GI

Answer 11

longitudinal ulcers typically over Peyer’s patches

Question 12

a patient presents with weight loss and chronic diarrhea. she also has symptoms of intestinal obstruction. what is the most likely IBD

Answer 12

IBD's present with chronic diarrhea and weight loss
intestinal obstruction (and malabsorption because Crohn's involves the ileum more commonly than UC) is more commonly seen with Crohn's due to the structures and ↑ wall thickening

Question 13

_______ (IBD) will have granulomas

Answer 13

Crohn’s

Question 14

granulomas are seen in ________

Answer 14

Crohn’s

Question 15

what is the preferred method of diagnosing C. difficile caused pseudomembranous colitis/

Answer 15

stool tests:

• enzyme immunoassay for toxin A/B
• PCR for tcdB gene

stool culture takes 2-4 days so not often used

Question 16

“string sign” on radiography is seen with ____

Answer 16

Crohn’s due to the wall thickening and strictures

Question 17

subserosal infiltrating fat (creeping fat) is seen in ________ (IBD)

Answer 17

Crohn’s; it is serosal reaction to the transmural inflammation

Question 18

pharmacologic administration of _______ (drugs) is associated with pseudomembranous colitis

Answer 18

↓ gastric acid secretion:

- PPI’s and H2 receptor inhibitors

Question 19

bacteria that triggers dendritic cells and a activates the T helper and _____ pathway ultimately leading to activation of neutrophils is the proposed mechanism of _____ (IBD)

Answer 19

T helper (TH2) and IL-8 pathway causing activation of neutrophils is the proposed mechanism of Ulcerative Colitis

Question 20

what are some associations of collagenous and lymphocytic colitis (microscopic colitis)

Answer 20

• NSAIDs
• celiac disease
• autoimmune: SLE, RA

Question 21

what layers are affected in TB caused colitis?

Answer 21

superficial as opposed to in Crohn’s, it is transmural

Question 22

pseudopolyps are seen in _____

Answer 22

UC; due to isolated islands of intervening regenerating mucosa bulge

Question 23

______ (inflammatory cell) is seen in the epithelium of the crypt (cryptitis) or in the lumen (crypt abscess) and is associated with ____ (IBD)

Answer 23

neutrophils; UC

Question 24

erythema nodosum is more commonly seen before/after the onset of GI symptoms and is seen more commonly in what IBD

Answer 24

erythema nodosum seen before the GI symptoms and more common in UC

Question 25

plasmacytosis and crypt abscesses are seen in _______

Answer 25

UC

Question 26

thinning of the luminal wall is seen in ____ (IBD)

Answer 26

UC

Question 27

pseudomembrane is a mixture of neutrophils, fibrin, and _____

Answer 27

necrosis; have damaged crypts that are distended with mucopurulent exudate

Question 28

endoscopy of ________ colitis is usually normal

Answer 28

microscopic; older women with watery diarrhea is the typical presentation with microscopic colitis

Question 29

while both UC and Crohn’s disease can have extra intestinal manifestations, which IBD are they more commonly seen?

Answer 29

UC

Question 30

______ (IBD) is associated with HLA DRB1

Answer 30

UC

Question 31

fistula and strictures are seen with _____ (IBD)

Answer 31

Crohn’s

Question 32

transmural inflammation is seen in _______ (IBD)

Answer 32

Crohn’s

Question 33

in addition to C. difficile, what is another cause of pseudomembranous colitis?

Answer 33

ischemia

Question 34

mucosa that is red, granular and friable is seen in _____

Answer 34

UC

Question 35

what type of granuloma is seen in Crohn’s

Answer 35

non caseating epithelioid granulomas

Question 36

______ is a histological feature seen in both Crohn’s and UC

Answer 36

crypt architectural distortion

but crypt abscesses is seen in UC