Path - Small Intestine and Colon Flashcards
extraintestinal manifestations of juvenile polyposis
congenital malformations and digital clubbing
diffusely flattened (atrophic) villi w/ intraepithelial CD8 T cells and loss of mucosal and brush border surface
celiac dz
pathogenesis of graft vs host dz
donor T cells target antigens on recipient’s GI epithelial cells
sporadic colon cancer: typical or mucinous adenocarcinoma?
- 70-80% of cases
- 10-15% of cases
- 5-10% of cases
70-80%: typical
10-15%: mucinous
5-10%: mucinous
sx of adult celiac dz vs pediatric celiac dz vs non-classic pediatric celiac dz
adult: chronic diarrhea, bloating, fatigue, anemia
pediatric: chronic diarrhea, irritability, abd distension, anorexia, weight loss
non-classic pediatric: abd pain, n/v, bloating, constipation
target gene of familial adenomatous polyposis
APC
acanthocytic red cells (burr cells)
abetalipoproteinemia
presence of dense subepithelial collagen later, increased intraepithelial lymphocytes, and mixed inflammatory infiltrate
collagenous colitis
what is the defect(s) of nutrient absorption in chronic pancreatitis
intraluminal digestion
demographic IBS
b/w ages 20-40
strong female predominance
extraintestinal manifestations of classic familial adenomatous polyposis
congenital retinal pigmented epithelium hypertrophy
compare genetic factor contribution b/w crohn dz and ulcerative colitis
crohn dz: genetic factors are more dominant, 50% in monozygotic twins
UC: 15% in monozygotic twins
how does ulcerative colitis begin in the GI tract and subsequently travel
begins in the rectum and extends proximally in a continuous fashion to involve all or part of the colon
extraintestinal manifestations of gardner syndrome (familial adenomatous polyposis)
osteomas, thyroid and desmoid tumors, skin cysts
fibrous bridge b/w viscera of the intestines
adhesion
development of numerous mucosal lymphoid follicles
diversion colitis
when does abetalipoproteinemia present
in infancy
where are colonic adenocarcinomas distributed in the colon
approximately equal length over the entire length of colon
compare clinical features b/w right sided and left sided colorectal adnocarcinomas
right sided: fatigue and weakness due to iron deficiency anemia
left sided: occult bleeding, changes in bowel habits, cramping and LLQ abd pain
mesenteric fat extending around serosal surface (creeping fat)
crohn disease
diagnostic criteria for IBS
abd pain or discomfort at least 3 days per month over 3 months with improvement following defecation and change in stool frequency or form
inheritance pattern of MYH-associated polyposis
AR
sx of autoimmune enteropathy
severe, persistent diarrhea and autoimmune dz
age of presentation of juvenile polyposis
less than 5 y/o
two most important prognostic factors for colonic adenocarcinoma
- depth of invasion
2. presence of LN mets
hereditary nonpolyposis colorectal cancer: typical or mucinous adenocarcinoma?
mucinous
two types of microscopic colitis
collagenous colitis and lymphocytic colitis
familial adenomatous polyposis: typical or mucinous adenocarcinoma?
typical
inheritance pattern of hereditary nonpolyposis colorectal cancer
AD
compare location in the GI tract b/w crohn disease and ulcerative colitis
crohn: any area of GI tract, transmural
UC: limited to colon and rectum, only into mucosa and submucosa
physical effects to the intestine from crohn disease
fibrosing strictures, fistulae, perforations
diarrhea due to failure of nutrient absorption that is relieved by fasting
malabsorptive diarrhea
target gene of sporadic colon cancer
- 70-80% of cases
- 10-15% of cases
- 5-10% of cases
70-80%: APC
10-15%: MSH2, MLH1
5-10%: MLH1, BRAF
clinical features of microscopic colitis (both collagenous and lymphocytic)
chronic, nonbloody, watery diarrhea without weight loss
what is the defect(s) of nutrient absorption in disaccharidase deficiency
terminal digestion
describe the gliadin induced damage that occurs in celiac dz
gliadin peptides induce IL-15 expression –> activates CD8T cells that express NKG2D –> attack MIC-A receptor on enterocytes –> cause epithelial damage –> enhances passage of gliadin peptides into lamina propria –> peptides interact w/ HLA-DQ2 or D8 on APCs –> stimulates CD4 T cells –> more tissue damage
what is the defect(s) of nutrient absorption in whipple dz
lymphatic transport
NOD2 polymorphism
crohn disease
predominant site of familial adenomatous polyposis
none
permanent entrapment of bowel segment due to venous stasis and edema
incarcerated hernia
GI lesions in peutz-jeghers syndrome
arborizing polyps most commonly in the small intestine
define Tis, T1, T2, T3, and T4 in regards to classification of colorectal carcinomas
Tis: in situ dysplasia or intramucosal carcinoma
T1: invades submucosa
T2: invades into, but not through, muscularis propria
T3: invades through muscularis propria
T4: penetrates visceral peritoneum or invades adjacent organs
two types of IBD
crohn disease and ulcerative colitis
clinical sx of intestinal obstruction
abd distension, vomiting, pain, constipation, tympanic by percussion
define MX, M0, M1 in regards to classification of colorectal carcinoma distant mets
MX: distant mets cannot be assessed
M0: no distant mets
M1: distant mets
describe how fasting affects each type of diarrhea
secretory: persists
exudative: persists
osmotic: lessens (abates)
malabsorptive: stops
genetic defect:
SMAD4, BMPR1A, TGF-B signaling pathway
juvenile polyposis
genetic defect:
APC/WNT pathway
familial adenomatous polyposis (FAP)
pathogenesis of IBD
combined effects of:
- alterations in host interactions with intestinal microbiotica
- intestinal epithelial dysfunction
- aberrant mucosa immune responses
- altered composition of gut microbiome
extraintestinal manifestations of peutz-jeghers syndrome
pigmented macules, risk of colon, breast, lung, pancreatic, and thyroid CA
skip lesions
crohn disease
most common malignancy of GI tract
adenocarcinoma
pathogenesis of IBS
poorly defined, but related to:
psychologic stressors, diet, perturbation of gut microbiome, increased enteric sensory responses to GI stimuli, abnormal GI motility
what are the only two diarrheal dzs that have defects in intraluminal digestion
chronic pancreatitis and CF
predominant site of involvement in sporadic colon cancer
- 70-80% of cases
- 10-15% of cases
- 5-10% of cases
70-80%: left side
10-15%: right side
5-10%: right side
complete twisting of a bowel loop about its mesenteric vascular base
volvulus
morphologic features of colonic diverticular dz
small, flask like outpouchings that occur in regular distribution alongside taeniae coli, most common in sigmoid colon
diarrhea due to excessive osmotic forces exerted by unabsorbed luminal solutes that abates w/ fasting
osmotic diarrhea
define NX, N0, N1, and N2 in regards to classification of colorectal carcinoma mets to LNs
NX: LN cannot be assessed
N0: no regional LN mets
N1: mets in 1-3 regional LNs
N2: mets in 4+ regional LNs
clinical features crohn disease
intermittent attacks of relatively mild diarrhea, fever, abd pain
20% pts w/ RLQ pain, fever, and bloody diarrhea
arterial and venous compromise due to pressure at the neck of a hernia
strangulation hernia
what is the defect(s) of nutrient absorption in abetalloproteinemia
transepithelial transport
clinical features of ulcerative colitis
bloody diarrhea with stringy, mucoid material, lower abd pain, cramping
diarrhea due to inflammatory disease leading to purulent, bloody stools that persist during fasting
exudative diarrhea
clinical features of colonic diverticular dz
most remain asymptomatic
20% have intermittent cramping, continuous lower abd discomfort, constipation, distention, or sensation of never being able to completely empty the rectum
class II HLA-DQ2 and HLA-DQ8 are associated with
celiac dz
what is the defect(s) of nutrient absorption in celiac dz
terminal digestion and transepithelial transport
compare presence of granulomas b/w crohn disease and UC
crohn: granulomas
UC: no granulomas
compare colonic adenocarcinoma tumors in the proximal colon and distal colon
proximal: polypoid, exophytic masses
distal: annular lesions
what is IPEX and what does it stand for
a severe familial form of autoimmune enteropathy
- immune dysregulation
- polyendocrinopathy
- enteropathy
- x-linked
extraintestinal manifestations of turcot syndrome (familial adenomatous polyposis)
medulloblastoma, glioblastoma
intestinal segment telescoping into immediately distal segment
intussusception
describe the classic adenoma-carcinoma sequence that causes colonic adenocarcinoma
mutation in APC –> accumulation of B-catenin and translocation to nucleus –> forms complex w/ TCF and activates transcription of genes including MYC and cyclin D1 –> promoted proliferation
extraintestinal manifestations of crohn disease
- uveitis
- migratory polyarthritis
- sacroiliitis
- ankylosing spondylitis
- erythema nodosum
- clubbing of fingertips
clinical features of graft vs host dz
watery diarrhea that can become bloody in severe cases
age of presentation of familial adenomatous polyposis
- classic
- attenuated
- gardner syndrome
- turcot syndrome
- MYH-associated polyposis
- classic: 10-15
- attenuated: 40-50
- gardner syndrome: 10-15
- turcot syndrome: 10-15
- MYH-associated polyposis: 30-50
ATG16L1 and IRGM polymorphisms
crohn disease
dietary factors associted with colonic adenocarcinoma
low intake of unabsorbable vegetable fiber
high intake of refined carbohydrates and fats
which IBD has risk of toxin megacolon
ulcerative colitis
what is the defect(s) of nutrient absorption in viral, bacterial, and parasitic gastroenteritis
terminal digestion and transepithelial transport
age of presentation of peutz-jeghers syndrome
10-15
11 is most common
predominant site of involvement in hereditary nonpolyposis colorectal cancer
right side
molecular defect in sporadic colon cancer
- 70-80% of cases
- 10-15% of cases
- 5-10% of cases
70-80%: APC/WNT pathway
10-15%: DNA mismatch repair
5-10%: hypermethylation
sx of abetalipoproteinemia
failure to thrive, diarrhea, steatorrhea
TTG antibodies
celiac dz
what is the defect(s) of nutrient absorption in cystic fibrosis
intraluminal digestion
compare ulcers b/w crohn disease and UC
crohn: deep, knife life ulcers
UC: superficial, broad-based ulcers
causes of intussusception in young children vs older children/adults
children: spontaneous or associated w/ viral infection or rotavirus vaccine
older children/adults: intraluminal mass or tumor
cobblestone appearance of mucosa w/ thickened intestinal wall
crohn disease
most common cause of intestinal obstruction in children under 2
intussusception
what is the only diarrheal dz that has a defect in terminal digestion
disacchardiase deficiency
effect of NSAIDs on risk for colonic adenocarcinoma
they REDUCE risk
- carcinomas use COX2 to make prostaglandins for proliferation of the polyp
- NSAIDs inhibit COX2
sx of environmental enteropathy
malabsorption, malnutrition, stunted growth, defective intestinal mucosal immune function
what is the defect(s) of nutrient absorption in IBD
intraluminal digestion and terminal digestion and transepithelial transport
molecular defect in MYH-associated polyposis
DNA mismatch repair
subepidermal blisters and granular IgA deposits
celiac dz
cause of diversion colitis
post-surgical ostomy with blind distal segment of colon from which normal fecal flow is diverted
normal thickness subepithelial collagen layer and great increase in intrapeithelial lymphocytes
lymphocytic colitis
genetic defect:
STK11; AMP kinase related pathways
peutz-jeghers syndrome
FOXP3 mutation
IPEX (familial form of autoimmune enteropathy)
dermatitis herpetiformis is associated with
celiac dz
what is the only diarrheal dz with a defect in lymphatic transport
whipple dz
what two pathways have been describes that can lead to colonic adenocarcinoma
APC/B-catenin pathway
microsatellite instability pathway
most frequent cause of intestinal obstruction worldwide vs in the US
worldwide: hernias
US: adhesions
what external triggers can re-activate crohn disease
physical or emotional stress, dietary items, and cigarette smoking
crohn disease can mimic what disease processes
appendicitis or bowel perforation
noncaseating granulomas in intestinal wall
crohn disease
paneth cell metaplasia
crohn disease
target gene of MYH-associated polyposis
MYH
predominant site of MYH-associated polyposis
none
HNFA polymorphism
ulcerative colitis
celiac dz most often affects what part of the GI tract
2nd part of duodenum to the proximal jejunum
compare sx b/w congenital lactase deficiency and acquired lactase deficiency
congenital: explosive diarrhea w/ watery, frothy stools and abd distension (after milk ingestion)
acquired: abd fullness, diarrhea, flatulence (after milk digestion)
protrusion of serosa lined pouch of peritoneum that can trap bowel segments externally
hernia
molecular defect in hereditary nonpolyposis colorectal caner
DNA mismatch repair
inheritance pattern of familial adenomatous polyposis
AD
target gene of hereditary nonpolyposis colorectal cancer
MSH2, MLH1
MYH-associated poyposis: typical or mucinous adenocarcinoma?
mucinous
isotonic (compared to plasma) stool that persists during fasting
secretory diarrhea
“napkin-ring” constrictions
adenocarcinomas in distal colon
what is the defect(s) of nutrient absorption in autoimmune enteropathy
terminal digestion and transepithelial transport
GI lesions in familial adenomatous polyposis
multiple adenomas
what is the defect(s) of nutrient absorption in environmental enteropathy
terminal digestion and transepithelial transport
most common areas for volvulus
redundant loops of sigmoid colon
chronic, relapsing abdominal pain, bloating and changes in bowel habits
IBS
child with mucocutaneous pigmentation and multiple hamartomatous polyps and intussusception
peutz-jeghers syndrome
lot of blood per rectum with malformed submucosa or mucosal vessels in cecum or right colon, 6th decade of life
angiodysplasia
celiac dz is most often associated with what malignancy
T cell lymphoma
erythema nodosum is associated with
crohn dz
