Small Intestine and Colon Pathology 2

Question 1

What are the two branches of inflammatory bowel disease?

Answer 1

crohns disease and ulcerative colitis

Question 2

Which one - UC or CD - will affect only the colon an drectum?

Answer 2

ulcerative colitis

Question 3

Which is continuous and which has skip lesions?

Answer 3

UC is continuous

CD has skip lesions

Question 4

What will you see pathologically with ulcerative colitis

Answer 4

1. dense lymphoplasmacytic inflammatory infiltrate
2. crypt architecture alteration with branched crypts
3. neutrophil crypt abscesses

these features will be seen in a uniform fashion thorughout the affected area

Question 5

What will you see pathologically with crohns disease

Answer 5

1. apthous ulcer formation with neutrophilic infiltrate (fissuring ulcers extending into submucosa)
2. non-caseating granulomas
3. grossly will see cobblestoning due to the fissuring
4. fat wrapping around to anti-mesenteric side

involvement will be patchy - normal mucosa will be right next door

Question 6

Which one has transmural involvement and which only invovles the mucosa?

Answer 6

UC is just mucosa

CD can be transmural

Question 7

What are the risks associated with the transmural involvement in CD?

Answer 7

stricture formation or perforation with associated with serositis

Question 8

Compare and contrast the CLINICAL presentations of UC and CD?

Answer 8

UD: bouts of bloody diarrhea with mucus discharge. lower abomdinal pain and cramps, tenesmus with proctitis

CD: variable presentation with mild diarrhea, fever, abdominal pain,

note that 10-20% of people with CD or UC will have extra-intestinal disease like sclerosing colangitis, erythema nodosum, pyoderma gangrenosum, iritis/uveitis

Question 9

Define and describe diversion colitis

Answer 9

After a diverting ostomy, the blind distal segment of the colon is excluded form fecal stream

this means that the bacteria in that segment don’t get food and won’t make any short chain fatty acids for the colonocytes and you get a colitis

if the fecal stream is re-established, the colitis regresses

Question 10

Define and describe radiation enterocolitis

Answer 10

epithelial damage occuring acutely due to radiation

chronic injury is often ischemic resulting from vascular injury with occlusion of blood vessels

patients can develop ulcers, strictures, fistulas and serosal adhesions - patchy erythema, hyalinization and thickening of blood vessel walls

radiation fibroblasts can be seen

Question 11

Define and describe neonatal necrotixing enterocolitis

Answer 11

transmural necrosis of the bowel due to bacterial overgrowth in the first week of life in premature infants

get will be made in the wall of the intestine which can be seen as air bubbles within the wall

happens because they have impaired GI defenses to mucosal injury

Question 12

What are the two types of microscopic colitis?

Answer 12

lymphocytic colitis
collagenous colitis

(treat with glucocorticoids)

Question 13

What is the typical pathologic and clinical presentation for lymphocytic colitis?

Answer 13

you get increased lamina propria chronic inflammation (especially plasma cells) along with increased intra-epithelial lymphocytes and surface epithelial damage
crypt architecture is intact

presents with chronic watery diarrhea - no blood

Question 14

What is the typical pathologic and clinical presentation for collagenous colitis?

Answer 14

A band of subepithelial collagen is seen in addition to the above inflammatory changes
crypt architecture is intact

also chronic watery diarrhea - no blood

Question 15

State the classes of drugs commonly implicated in drug induced enterocolitis.

Answer 15

NSAIDs
chemotherapeutic agents
antibiotics leading to pseudomembranous colitis

Question 16

Define and describe irritable bowel syndrome.

Answer 16

it’s chronic, relapsing abdominal pain, bloating and changesin bowel habits in the absense of any known causative agent that could explain the symptoms

it’s split into different subtypes based on stool consistency: constipation predominant, diarrhea preodminant, mixed-subtype and unsubtyped

pathogenesis unknown

Question 17

Define and describe sigmoid diverticulitis

Answer 17

formation of multiple diverticulae, usually in the sigmoid colon

the diverticulae (tics) can become inflamed to form diverticulitis

pathogenesis related to increased intra-luminal pressure in the sigmoid colon from a lack of fiber in the diet

Question 18

What are the common complications of sigmoid diverticulitis

Answer 18

Most people with diverticulae are asymptomatic unless you develop diverticulitis, in which case, perforation, fistula formation, obstruction, abscesses are potential complications

you can also get an inflammatory colitis referred to as diverticular disease-associated colitis

Question 19

Define and describe solitary rectal ulcer syndrome

Answer 19

It’s a disorder caused by malfunction of the puborectalis muscle leading to excessive straining on defacation

straining results in prolapse which contributes to ulceration and formation of inflammatory polyps that can bleed

presents with bloody stools, pain with defecation and alternating constipation and diarrhea

Question 20

Describe the clinical significance and morphology of inflammatory polyps

Answer 20

This is just a normal reaction to inflammation in the GI tract - not a neoplastic process

associated with conditions like solitary rectal ulcer syndrome, ulcerative colitis or crohn’s disease

can occur anywhere along the GI tract

sometimes called inflammatory pseudopolyps in UC and DC

Question 21

Describe the clinical significance and morphology of juvenile (retention) polups

Answer 21

A hamartomatous polyp that occurs in young children and adults - can be sporadic or as a result of a polyposis syndrome

affect colon and rectum, typically solitary unless associated with a juvenile polyposis syndrome

sporadics have NO icnreased risk of malignancy, but people with juvenile polyposis syndrome are at higher risk for aenocarcinomas

polyp is smooth, unilobular with an erythematous cap of eroded tissue - histologically filled with multiple dilated mucin filled crypts leading to the term mucin retention polyp

can bleed if symptomatic

Question 22

Describe the clinical significnance and morphology of Peutz-Jaghers polyps

Answer 22

polyp that occurs in peutz-jeghers syndrome

mucocutaneous hyperpigmentation and multiple polyps in the small bowel, colon and stomach

have a characteristic arborizing smooth muscle pattern - frequently peunculated

patients can present in childhood with GI bleeding and intussusception

Question 23

Describe the clinical significance and morphology of a hyperplastic polyp

Answer 23

Usually occuring in the colon - most common type of adult colonic polyp

they are small and usually found in left colon (usually rectum) - can be single ot multiple

probably just a proliferative polyp without significant malignant potential. However, they need to be distinguished form sessile serrated adenomas and serrated adenomas, which are neoplastic polyps

Question 24

Describe the clinical significance and morphology of adenomatous polyps

Answer 24

a neoplastic polyp characterized by dysplastic glandular proliferation

it can consist largetly of a tubular proliferation of glands or a more villous proliferation

usually in colon but can be in small bowel - esp ampulla of duodenum

can be precursors to adenocarcinoma, although most do not become maliganant. Needs to be completely removed either way

Question 25

Describe the clinical significance and morphology of sessile serrated adenoma

Answer 25

it’s a sessil polyp that looks like a hyperplastic polyp, but it can be a precursor to adenocarcinoma

lack the classic adenomatous epithelium of the conventional adenoma

often seen in right colon

complete polypectomy on colonoscopy is necessary

Question 26

Describe the clinical signifiance and morphoogy of a serrated adenoma

Answer 26

This exhibits serration along the uniform eiosinophlic dysplastic epithelium

also can be precursors for adenocarcinoma, so do polypectomy

Question 27

How can you differentiate a sessile serated adenoma from a hyperplastic polyp?

Answer 27

the hyperplastic polyps will have crypts that narrow down into Vs at the bottom

the sessile adenoma crypts widen at the bottom

Question 28

Think back….If someone has indeterminate colitis, what lab tests can help differentiate UC and CD?

Answer 28

CD is ASCA positive

UC is pANCA positive

Question 29

WHat are the major complications of UC?

Answer 29

fulminant colitis with toxic megacolon and perforation

Question 30

WHat are the major complications of CD?

Answer 30

small bowel stricutres, bowel obstruction, bowel perfortaoin from fistula formation

perianal fistulas, enterocutaneous fistulae, rectovaginal fistulas, enterovesicle fistulas.

Question 31

WHat’s the neoplastic conern with IBD?

Answer 31

both can cause dysplasia leading to adenocarcinoma

Question 32

What are some of the hypotheses regarding IBS pathogenesis?

Answer 32

1. decreased/increased colonic contraction and transit times
2. excess bile acid synthesis or malabsorption of bile acids
3. disturbances in enteric nervous system function
4. immune activation or shift in gut microbiome

Question 33

What are the Rome III diagnostic criteria for IBS?

Answer 33

recurrent abdominal pain or disomfort at least 3 days per month in the last 3 months associated with 2 or more of the following:

1. improvement with defacation
2. onset associated with a change in frequency of stool
3. onset associated with a change in form of stool

Question 34

Why are people with Peutz-jegher syndrome at higher risk for adenocarcinoma?

Answer 34

they have a loss of function mutation of STK11 which is a tumor suppressor gene