Small and Large Intestines Flashcards
Inflammatory bowel disease (IBD) definition:
example diseases?
- chronic relapsing inflammatory disorders of intestinal tract of obscure origin affecting GI tract
- Crohns and ulcerative colitis
pathogenesis of IBD
not well understood - could result from unregulated and exaggerated immune responses to normal gut flora
-M-cells have some abnormal regulation or presentation
WHcih immune cells are primary culprits in Crohns and UC?
T-cells and their products
which hypersensitivity reslts in Crohns?
chronic delayed type
Excessive stimulation of TH2 cells in which condition?
IBD –> ulcerative colitis!
TH2 cells stimulated in which condition?
UC
Which condition is a transmural inflammation - through bowel wall?
CD
CD - defintion:
-idiopathic, chronic ulceroconstrictive inflammatory bowel disease characterized by:
~sharply delimited and typically transmural involvement of bowel by an inflammatory process with mucosal damage
~presence of non-caseating granulomas
~fissuring with formation of fistulae
~sytemic manifestations in some patients
Whcih condition has inflammation that is limited to mucosa?
UC
Affected area CD vs UC?
Crohns can be anywhere in GI tract vs UC only in intestines
People affected - CD:
- peak in 20s and 30s but any age
- Whites
- Females
- jewish population
- SMOKING IS A STRONG RISK FACTOR
CD patient presentation:
- All have diarrhea - can be bloody
- fever
- pain,
- WL
- weakness
- anemia
ALL DUE TO TRANSMURAL INFLAMMATION
Which condition has higher CA risk, CD or UC?
UC has higher risk
CD - long term issues:
- malabsorption
- inc risk of carcinoma (but not as high risk as with UC)
- amyloidosis
Morphology of CD
- segmental - skip lesions
- Early APHTHOID ulcers - linear
- COBBLESTONE MUCOSA
- thickened, inflexible way (RUBBER HOSE) - Luminal narrowing
- CREEPING FAT - dull gray, granular serosa
- Fissures and fistulous tracts, abscess formation
Whcih condition has skip lesions and which is continuous?
CD=skip lesions but transmural
UC=continuous but only in mucosa
**Main histological difference bw UC and CD?
**CD has non-caseating granulomas
String sign on radiology?
thickening of bowel in CD
wHich condition has more primary sclerosing cholangitis?
UC more than CD!
Crohns disease extraintestinal manifestations:
- migratory polyarthritis
- sacroiliitis
- ankylosing spondylitis
- erythemia nodosum
- clubbing of fingertips
- primary sclerosing cholangitis (less than seen with UC)
- mild hepatic pericholangitis
- uveitis
UC- definition:
ulceroinflammatory disease limited to colon and affecting only mucosa, submocusa
- extends CONTIGUOUSLY (NO SKIP LESIONS) proximally from rectum
- NO GRANULOMAS
- systemic disorder
NO granulomas with which condition?
UC!
Thinning of the bowel vs thickening of the bowel conditions?
Thinning = UC THickening = CD
First place affected in 50% of UC patients? How it presents?
rectum = BLOODY MUCOID DIARRHEA!*
Ulcerative colitis morphology:
- rectum involved
- continuous proximal involvement
- BACKWASH ILEITIS - debris washed back into ileum if through whole colon
Chronic UC has:
-coalescence of ulcers and pseudopolyps
Complication of UC?
toxic megacolon
perforation
Only affect part or all of colon?
UC
Histology of
1) Active UC:
2) chronic UC:
1) -mononuclear infiltrate in lamina propria
- crypt abscesses (PMNs in crypts)
- dystortions of crypts
- ulcerations
- granulation tissue
- NO GRANULOMAS!!!!
2) ulcerations
- submucosal fibrosis
- POSSIBLE CARCINOMA
- flat dysplasia
- atrophy
- mucosal glad disarray
Inflammatory pseudopolyps seen in:
UC!
Muscularis propria and serosa are unaffected in which condition?
UC
Presentation UC?
- remitting and relapsing with stress as precipitant
- lower abdominal pain, cramps
- relieved by pooping
- BLOODY MUCOID POOP
MAIN COMPLICATION OF UC?
What drives this complication?
CARCINOMAS!! - usually no obvious mass!!! - early diagnosis is critical
DNA damage and microsatelite instability in mucosal cells
***Results of transmural infiltration in CD?
Serosa inflamed adhesions fistulas perianal abscess and fistula granulomas
Does UC or CD have potential for megacolon?
UC!
Ischemic colitis is what kind of disease?
Where most often occurs?
- vascular disorder
- most often occurs in “watershed” areas of splenic flexure (SMA and IMA) or rectosigmoid (IMA and hypogastic)
causes of Ischemic colitis?
- multifactorial!
- arterial embolism
- arterial thrombosis
- low flow states (non-occulusive)
- venous thrombosis
- miscellaneous - radiation, volvulus, stricture, herniation
transmural infarction is due to:
Its gangrene due to acute vascular obstruction
Mural and mucosal infarction due to?
acute or chronic hypoperfusion
NO SEROSAL INVOLVEMENT
What kind of diarrhea with mural and mucosal infarct?
bloody diarrhea
Transmural infarction (gangrene):
- what layers involved?
- most common cause?
- mortality?
- all layers! comprise of MAJOR blood vessels
- thrombosis or embolism of SMA in 50% of cases
- rapid progression to shock and death - for sure dead if not immediately removed
Cronic ischemia:
- think of what kind of patient
- what happens?
-older patient with inflammatorry bouts
inflammation ulceration and fibrosis - may lead to stricture
-may have some bloody diarrhea
Angiodysplasia
- what is it?
- what layers involved?
- problem with most cases?
- non-neoplastic vascular dilation and malformation of submucosal blood vessels in cecum and ascending colon
- mucosa and submucosa
- significant bleeding of lower intestines = trouble
Lots of frank red blood flowing think which disease?
angiodysplasia
or
diverticular disease
diverticular disease
-due to?
increased abdominal pressure
meat eating
others tuff
where is most diverticular disease?
sigmoid colon - weak areas of submucosa and muscularis propria where small mesenteric vessels penetrate muscularis propria
pathogenesis of diverticular disease?
- focal weakness in colonic wall coupled with increased luminal pressure
- low fiber diet
Clinical presentation of diverticular disease
most are asymptomatic
What do diverticula look like with barium CT?
saw-tooth pattern
complications of diverticular disease:
- when inflammed - deverticulitis = most common
- when rupture
Intestinal obstruction
- what part of intestine most often affected?
- conditions most patients with this have?
- usually involves small bowel
- Hernias, adhesions, intussusception, volvulus
Why does obstruction cause pain?
bc distention can cause pain!!
Hernias:
- definition:
- typical regions?
- may cause what issues?
- outpouching of peritoneum through defect or weakness in abdominal wall; serosa lined sac of peritoneum; external herniation
- typically inguinal and femoral regions
- umbilical if surgical scars
- may cause incarceration and strangulation
Inguinal hernias
-types:
direct: IN ADULTS- medial to inf epigastric vessels - weakness in hasselbacks triangle
indirect: lateral to inf epigastric vessels - congenital or acquired in adulthood - can go down into testes
adhesions
- what are they?
- when can they happen?
- what can happen because of adhesions?
- fibrous bridges between bowel segments or abdominal wall
- following inflammation (peritonitis), surgery, infection, endometriosis - RARELY CONGENITAL
- viscera can slide between the fibrous bridges and become trapped
- obstruction and infarction
intussusception
what is it?
issue with this?
- proximal egment of bowel telescopes into a distal segment of bowel by wave of peristalsis
- leads to infarction
volvulus think:
TWISTING OF BOWEL
Volvulus:
- issues when this happens?
- most frequent in who and which bowel?
- ischemia and necrosis
- most frequent in children - small bowel
- adults get in small and large bowel
steatorrhea definition:
malabsorption of fat - abnormal bulky, frothy, greasy, yellow or gray stools
symptoms of malabsortion
- steatorrhea
- WL
- anorexia
- abdominal distention
- borborygami
- muscle wasting
Most common Malabsorptive disorders in US?
-celiac sprue
chronic pancreatitis
-crohns
Malabsorptive disorder cause in OUS?
problems of infectious causes
celiac sprue;
1) what is it?
2) characteristic mucosal biopsy?
3) diagnosis?
4) TX?
5) issues?
1) genetic susceptibility - exposure to gliadin = T-cell mediated chronic inflammatory reaction
2) vilous atrophy
3) Hx, biopsy, response to diet
4) gluten free diet
5) malabsorption
Tropical sprue
1) what is it?
2) where is it?
3) what happens?
1) Entire small intestine affected –> folate and/or B12 deficiency (megaloblastic changes) in intestinal epithelial cells
2) tropical disease - india, caribbean, africa, SE Asia, Central and S America
3) Bacterial overgrowth = use borad spectrum antibiotics
Whipple Disease
1) what is it?
2) what does it effect?
3) who is affected?
1) tropheryma whippelii - organism lives in macrophages
2) systemic disorder - intestine CNS and joints = severe malabsorption, diarrhea, steatorrhea, emaciation, fever, polyarthritis
3) middle ages whites - 10 Males to 1 Female
Whipple disease - hallmark
- macrophages are stuffed with PAS + granules from Tropheryma whippelii a gram pos actinomycete
- pretty mcuh goes everywhere
Vili with foamy macrophages and stains PAS + what issue?
Whipple Disease
WHat is the most common tumor of GI tract?
adenocarcinomas
most common tumors of small bowel?
adenocarcinomas and carcinoid
small bowel tumors not as common as large bowel
Most frequent benign tumors of small intestines?
adenomas, mesenchymal tumors (GISTs)
most common site for adenoma of small bowel?
ampulla of vater - where common bile duct comes in == pateints present with jaundice
What genetic condition increases risk for small bowel adenoma?
familial polyposis coli (FPC)
What inflammatory condition increases risk of small bowel adenoCARCINOMA?
crohn disease
small bowel adenocarcinoma - distinctive feature:
“napkin ring” - encircling pattern or as polypoid masses similar to colonic carcinomas
Adenocarcinoma more common where and hwat part?
more common in large bowel - rectum to sigmoid is hotspot
polyps start wth what appearance and grow to have?
all are sessile and form stalk (pedunculated)
most non-neoplastic polyps how formed?
formed as result of abnormal mucosal maturation, inflammation, or architecture (HYPERPLASTIC POLYP)
most common neoplastic polyps:
adenomatous polyps (adenomas) - precursors to CA = epithelial polyps arise as result of proliferation and dysplasia
Hyperplastic polyps: are these common? ***where are they? what kind?
common
***benign in recto-sigmoid area
harmartomatous polyps:are these common? where are they? what kind?
-normal tissue components arranged abnormally
may be part of familial syndrome
inflammatory polyps - seen with what disease>
seen in IBD
cause of hyperplastic polyps:
malignant potential?
- pdecreased epithelial cell turnover and delayed shedding with accumulation of mature cells on surface
- no neoplastic potential
Which polyps are juvenile and retention polyps?
juvenille LARGER happen in childern = hamartomatous polyps
rentention SMALLER polyps happen in adults
What happens with juvenile polyposis syndrome?
young patient has juvenille polyps (hamartomatous) but has increased risk of adenomas and adenoCA
Peutz jeghers polyps - how happens? new risks?
- a hamartomatour polyp WITH MUCOCUTANEOUS PIGMENTATION but there is a mutation in STK11 gene
- risk for intussusception!
adenomas polyp is precursor to
colorectal CA
most important determinant of adenomas?
SIZE!!
four types of neoplastic adenomatous polyps?
tubular
tubulovillous
vilous
serrate
Most common adenomatous polyp?
tubular
TUbular adenomas:
most common, least likely to be malignant, larger ones pedunculated (stalk)
tubulovillous adenomas:
mostly tubular, malignancy risk intermediate
vilous adenomas:
sessile, broad based tumors
usually large frequently contain carcinoma
serrated adenomas:
overlap with hyperplastic polyps histologically; most in right colon, full thickness serration
intramucosal carcinoma
breached basement membrane to invade lamina propria or muscularis mucosa, no metastatic potential
Villous adenomas: when is there an increased risk for CA?
if it is >4cm
Villous adenomas - propensity to be where in GI? Causes?
rectum and rectosigmoid
causes bleeding - protein losing enteropathy
What is trouble with removing villous adenomas?
they have no stalk
Tubulovillous adenomas
- appearance?
- risk of CA?
- usually have a stalk
- CA risk depends on how villous it is
factors determining dev of CA in adenomatous polyps?
SIZE
proportion of villous component
degree of dysplastic change
Adenomas presentation?
present secondary to?
usually asymptomatic
bleeding - esp anemias / iron def anemia
Villous adenoma presentation?
symptomatic - overt rectal bleed and mucous secretion which can lead to hypoproteinemia, hypokalemia
Whcih adenoma type has little or no metastatic potential?
- intramucosal CA with lamina propria
- hgih grade displasia (CIS)
==> these are benign
Which adenoma type can metastasize?
invasive adenoCA - Crosses muscularis mucosa
3 criteria that must be met to have adequate excision of pedunculated adenoma with invasive CA?
1) AdenoCA is superficial, does no approach margin of excision across base of stalk
2) no vascular or lymphatic invasion
3) CA is not poorly differentiated
surgery for invasive CA arising in pedunculated or sessile polyp -
cannot use polypectomy- must remove part of bowel - complete resection
colorectal CA risk factors:
1) increasing ages
2) prior colorectral CA or polyps
3) UC or CD
4) genetics
5) diet
older male patient with iron deficiency anemia… what must be ruled out?
GI carcinoma until proven otherwise
GI carcinomas like to send mets to…
LN, LIVER, LUNGS and BONE
What is cause of left side colorectal CA?
solid stool passing by - tumor is a little smaller maybe
What is cause of Right sided colorectal CA?
anemia 2ndary to blood loss - watery poop still in this area so tumor can grow a lot more
Thin pencil like poops?
annular CA on left side - napkin ring lesion
Classical FAP syndrome due to what mutation?
mutations in adenomatosis polyposis coli (APC) gene
Classic FAP syndrome - prognosis
ALL will develop CA before age 30
Attenuated FAP syndrome due to what mutation?
APC and MUTYH
Presentation of attenuated FAP?
delayed appearance of colon cancer - around age 50
Location of most tumors in Attenuated FAP?
proximal colon
Gardner syndrome - how different from FAP?
- same everything as FAP but ALSO distinctive extraintestinal manifestations (skull and mandible, epidermal cysts, cancer near teeth … lots more)
Turcot syndrome:
- what is it?
- how different from FAP?
- combo of colonic polyposis and tumors of CNS
- 2/3 have development of medulloblastomas if APC gene mutated
- 1/3 have glioblastomas due to mutations in DNA repair genes
Turcot think:
COLON AND BRAIN
What is Lynch Syndrome? where affect?
–HNPCC- hereditary nonpolyposis colorectal cancer
–usually right colon but increased risk of many organ extraintestinal adenoCA (especially endometrial)
Hallmark of HNPCC (Lynch syndrome) - which defects?
mutations in genes for detection, excision, and repair of DNA during replication
*MSH2 and MLH1**
MSH2 and MLH1 think what disease?
Lynch - or HNPCC
HNPCC inheritance pattern?
autosomal dominant
Poorly differentiated colon CA may have what appearance?
signet ring
staging for colorectal adenomCA?
TNM staging 0 in mucosa 1 in mucosa and muscularis propria 2 deeper in muscularis propria 3 = into LN 4 = seeded to other organs
Modified dukes staging (astler coller)
Stage A and B?
A= limited to mucosa B1 = extending into muscularis propria B2 = transmural but no LN
A and B best 5 yr survival
Carcinoid tumors - main sites?
GI tract and lung
Most common site for carcinoid tumors?
appendix
Carcinoid appendix and rectal cancers and metastasis
VS
ileal, gastric, and colonic corcinoids and metastasis?
rarely metastasize
FREQUENTLY METASTASIZE
If a carcinoid tumor gives met to liver we call it
features:
carcinoid syndrome - flushing of skin, cyanosis, diarrhea, cramps, nausea, vomiting
What kind of cell and secretion from carcinoid tumor?
neuroendocrine tumor
secretes serotonin
TEst for carcinoid tumor?
check for serotonin metabolism product in urine 5-HIAA
Most common extra nodal side for lymphoma? what cell type?
GI - B-CELLS
Three main types of GI lymphona:
MALT
sprue associated
mediterranean
Mediterranean GI lymphoma
- which cell?
- prognosis?
B- cell - plasma cells that secrete IgA heavy chains
B-cell prognosis better
Sprue associated GI lymphoma
- which cell?
- prognosis?
-T-cell
- younger PATIENTS 30-40 yrs
poorer prog than with B-cell
Main risk factor for GI lymphoma?
H Pylori! aka chronic gastritis
Malt lymphoma
- which cell?
- prognosis?
- B-cell
- better than t-cell
- most common in stomach SInce MALTOMA CAN BE IN ANY GI LYMPH TISSUE - H Pylori related
immunoproliferative small intestine disease is also called?
mediterranean lymphoma
GIST tumors from what cell type
what mutation?
kajal cells - MASS OF SPINDLE DELLS
mutation in c-KIT a tyrosine kinase receptor
mass of spindle cell tumor -which is it?
GIST!
most common acute abdominal condition?
appendicitis
First clinical sign of appendicitis?
THEN?
LOSS OF APPETITE
Periumbilical pain inRLQ
Histologic criterion for appendicitis?
PMNs inmuscularis propria
Most common tumor of appendix?
carcinoid
Nests of uniform looking cells whcih tumor?
carcinoid
