MOD (more IBS/IBD etc stuff)

Question 1

Diff between acute and chronic colitis in terms of histo?

Answer 1

acute (NOT IBD)–straight crypts, normal bowel with neutros
chronic–distortion of normal architecture (not straight crypts), paneth cell dysplasia (usu only SI) and pseudopyloric metaplasia (int starts to look like stomach with branching crypts and mucinous glands), fibrosis

Question 2

Cx of Chron’s?

site, what site is spared, what happens after resection, gross appearance, wall etc

Answer 2

• commonly occurs at terminal ileum (w/ prox colon), spares rectum, but can affect any part of GI tract
• can easily recur after resection
• skip areas of inflammation, and transmural (entire wall) inflam
• CHRONIC

Question 3

Chron’s sx/complications

Answer 3

Pain, diarrhea or constipation, obstruction, dysplasia, carcinoma, perianal disease, and fistulas from transmural inflam
-can also lead to pydoerma gangrenosum, toxic megacolon, arthritis, spondy, oral ulcers, erythema nodosum

Question 4

Chron’s pop?

Answer 4

teens-20s, and 50s-60s (same w/ UC!)

caucasian (same w/ UC)

Question 5

More chron’s path/ histo/ gross/ complications

Answer 5

• transmural inflammation with skip areas
• mucosal crypt distortion and metaplasia
• COULD have noncaseating granulomas
• could have fissures and fistulas
• fibrosis
• creeping fat, neuronal hyperplasia
• COBBLESTONING is common

Question 6

Which cancer can occur from chron’s

Answer 6

adenocarcinoma of intestine (more likely to occur when more bowel is involved)

Question 7

UC site involved?

Answer 7

COLON ONLY! (mucosa) (starts at rectum and moves up)

Question 8

UC complications?

Answer 8

can have bloody diarrhea

-stricture and toxic megacolon

Question 9

UC path/gross

Answer 9

continuous inflammation and diffuse discoloration and flattening of mucosa (ONLY inv mucosa!)

• can also get basal plasmacytosis w branching crypts, and inflam pseudopolyps (continuous)
• architectural distortion (sign of CHRONIC colitis)

Question 10

What type of cancer is commonly involved in UC and what does it look like?

Answer 10

SIgnet ring cell adenocarcinoma

and mucinous

Question 11

Chron’s vs UC anatomy

Answer 11

Chron’s: ileum and colon, skip lesions, thicc wall

UC: COLON ONLY, diffuse spread, thin wall

Question 12

Chron’s vs UC histo

Answer 12

Chron’s: transmural inflam, deep ulcers/fissures, can have granulomas, can have fistulas, marked fibrosis

UC: mucasal inflam only, superficial ulcers, NO granulomas or fistulas, MILD fibrosis

Question 13

IBS hallmarks?

Answer 13

abdominal pain and alterations of bowel fxn (const or diarr)

Question 14

Rome III criteria

Answer 14

for IBS:
pain for at least 3 days a month in last 2 months, sx for 6 months total
-must have 2 of following: improve pain with defecation, change in freq of stool, change in appearance of stool
-v common!

Question 15

IBS pop?
What plays a major role in IBS?
more ibs hallmarks?

Answer 15

v common in US, west europe. east asia, no socioeconomic assoc

• often younger women
• gut brain axis plays major role (enhanced perception of pain, hypersensitivity, altered motility)
• prolonged gastrocolic reflex (takes longer to expel after eating)

Question 16

What other dis is IBS linked to

Answer 16

noncardiac chest pain, fatigue, fibro etc

-may also have sx that mimic IBD, psychosocial issues

Question 17

Role of serotonin in IBS?

Answer 17

enterochrom cells rel serotonin, goes to myenteric plexus and stim peristalsis, leaky gut, microbiome
-ACh and NO may also mediate motility, tachys and bradys may also mediate visceral sensitivity

Question 18

red flags that may be alternative to IBS?

Answer 18

anemia, weight loss, lots of blood (eg test for celiacs etc)

Question 19

IBS tx?

Answer 19

biofeedback, therapy, diet, tricyclics and antispasmotics to relax GI, antiflat/dig enz, antidiarrh, probiots, fiber, lax, cl channel agents

Question 20

Ischemic bowel disease and sx?

Answer 20

decreased blood flow to intestine, an cause occulsion of mesenteric aa resulting in acute onset abd pain and ELEVATED LACTIC ACID

Question 21

levels of ischemic dmg?

Answer 21

mucosal, mural (mucosal/submucosa), and transmural

as size of bv gets larger, injury goes deeper

Question 22

what is chronic ischemia often due to?

acute?

Answer 22

atherosclerosis, 2+ major arteries injured

-acute: thrombus or clot, quick onset and high lactic acid/ bloody stool, transmural

Question 23

How does vascular ischemia progression appear gross/histo?

Answer 23

congested dusky red tissue
micro-submuc edema, ecchymosis, hemorr, thickening, then lose distinctino of muscle layers and get blood in lumen (maybe gangrene), erosion of mucosa, ischemic dmg with crypts reduced, lots of red
-may see black/purple tissue from infarct among scope examination (dont want to risk perforation)

Question 24

Histo of ischemic dmg

Answer 24

erosion of mucosa, fibrosis, ischemic dmg, cr

Question 25

3 main categories of causes of malabsorption?

Answer 25

Secretory insufficiency, imparied motility, and impaired mucosal function!

Question 26

causes of secretory insuff in malabs?

Answer 26

biliary obstruction, and pancreatic enz insuff (eg alc, CF)

Question 27

causes of impaired motility in malabs?

Answer 27

diab neurop, amyloidosis and scleroderma, also BLIND LOOP sydnrome (section of SI doesnt have normal digestive flow usu from surgery)

Question 28

causes of impaired mucosal fxn in malabs?

Answer 28

from short bowel syndrome, sprue (blunting of villi), lymphomas, inflamm disease eg chrons, whipple dis

Question 29

Which dis result in villous atrophy?

Answer 29

``` celiac sprue (diffuse atrophy) bacterial overgrowth (patchy atrophy) infectious gastroenteritis (patchy) tropical sprue (usu bacterial) (entire SI) kwashiorkor (protein deficiency) ```

Question 30

Celiac - what can it lead to - histo - dx

Answer 30

ANEMIA, FLAT VILLI, IgA/HLA dx - can lead to anemia and iron/folate/b12 def, compl include primary T cell lympoma, ulceration of SI, collagenous sprue - flat villi and more lymphos, elong crypts - serology for IgA, gen test for HLA markers etc

Question 31

``` Whipples disease cause? sx? pop? histo? ```

Answer 31

rare bacterial sys infxn that affects intestine, cns and joints - eg middle aged white male with fever, malabs, weight loss, arthirits, and lymphadenopathy (from tropheryma whippelii) - histo: extension of lamina propria by foamy macros, PAS positive granules, rod shaped bacilli

Question 32

What genetic changes can change adenomas to adenocarcinomas in SI?

Answer 32

multi hit theory | ras, 5q21, los of 18q or tsg p53 etc

Question 33

Adenomatous polyps (adenoma)

Answer 33

benign but can become cancer | slow, can be tubular or villous (fingerlike projections, but rare) or both

Question 34

Serrated polyps?

Answer 34

adenoma with sawtooth pattern due to infolding/shark tooth, crypts lined w goblet cells, uniform glands mostly parallel) -serrated polyps can be hyperplastic polyps (no malig) or serrated adenomas (with epith dysreg, can lead to microsatellite instability which can be seen in Lynch synd) (disorg nonuniform glands w pinkish mucus)

Question 35

when is a tumor considered malig?

Answer 35

when it goes into submucosa (past mucosa) and penetrates BM

Question 36

carcinoma in situ?

Answer 36

not malig, high grade dysplasia, stays in epith or extends into lamina prop (in mucus)

Question 37

colon risks prevention

Answer 37

smoking, alc, red meat maybe, obesity and sendentary, AA, IBD, fHx -prevent wiht fruits/veg, Ca/dairy, high fiber, whole grains etc, colonoscopy at 45 yo

Question 38

screening/testing for colon cancer>

Answer 38

AA age 45 - fecal IHC test to detect abs to hb (better than fecal guiac) - colonoscopy and snip out polyp

Question 39

how do colon adenocarcinomas appear in right vs left colon

Answer 39

right (cecum etc)--polypoid, fungating lesion w raised edge (fewer sx than left) -left: annular napkin ring lesion with heaped up edge (can have iron def anemia from GI bleeding)

Question 40

adenocarcinoma general appearance? sx? results? assoc with Lynch synd?

Answer 40

-both can get central necrosis, usu well-diff, but CAN be poorly sometimes (mucinous, signet ring tumors, of which are assoc with Lynch synd)

Question 41

What are ~6 sx assoc with colon cancers? Which one is AR?

Answer 41

``` Lynch syndrome FAP (fam adenoma polyposis) MYH polyposis [AR!] Puetz-Jegher's syndrome Juvenile polyposis syndrome Appendicular tumors ```

Question 42

``` Lynch syndrome genetics/dysfxnl genes? MSI? appearance? site? assocs? Tx? best testing/prevention? ```

Answer 42

- AD, dysfxn with mismatch repair prot, allowing small errors to accum (microsat instability, most occur in MSH2 and MLH1 genes, some others) - RIGHT colon - signet ring or mucinous (atypical adenocarc) - avg age dx 45 - MSI testing, but IHC best bc dir tests for MMR expression, colonoscopy 10 yr earlier than age of dx of family hx, may req SUBTOTAL colonectomy maybe hysterect

Question 43

``` FAP genetics assoc attenuated FAP tx/prevention? ```

Answer 43

thousands of small polyps throughout colon - mutation of APC gene - assoc with duod adenocarc and congen hypertrophy of retinal pigmented epith, duod/periamp/amp adenomas - Attenuated FAB if mtuation on side of gene, toned down with <100 - polyps, later in life but colon cancer still likely - kids should get sigmoidoscopy, thyroid ultrasounds bc risk of thyroid dis, may req total proctoectomy (w rectum) (atten is subtotal)

Question 44

Puetz Jegher

Answer 44

mutation STK11, pigmented spots on lips/buccal mucosa (hallmark!)

Question 45

Juvenile polyposis sydnrome

Answer 45

AD, germline mutations in transformaing growth factor beta signaling path

Question 46

appendicular tumors

Answer 46

v rare, mostly carcinoid which can lead to carcinoid (serotonin) syndrome, which looks like red sweaty asthmatic

Question 47

Size of appendicular tumors that have risk of metastasis

Answer 47

2 cm