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2020 GI II Exam 1 > Chapter 17: Small Intestine and Colon > Flashcards

Chapter 17: Small Intestine and Colon Flashcards

1
Q

Acquired hernias most typically occur anteriorly via which sites?

A
  • Femoral and Inguinal canals
  • Umbilicus
  • Surgical scars
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2
Q

Which type of hernia is most often associated with obstruction and why?

A
  • Inguinal hernias
  • Narrow orifices and large sacs
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3
Q

What is the most common cause of intestinal obstruction in the US?

A

Adhesions

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4
Q

What do adhesions between bowel segments create and what does this lead to?

A

Create closed loop segments, trapping other parts of small bowel —> internal hernias

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5
Q

Although rare, where does Volvulus of the bowels most often occur?

A

Sigmoid colon > cecum > small bowel > stomach

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6
Q

What is the most common cause of intestinal obstruction in children <2 yo?

If left untreated may progress to what?

A
  • Intussusception
  • Untreated = intestinal obst. –> compress mesenteric vessels –> infarction
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7
Q

Although typically idiopathic, some cases of intussusception have been associated with what?

A
  • Viral infections
  • Rotavirus vaccine
  • Intraluminal mass or tumor (adults)
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8
Q

What is used both diagnostically and therapeutically for intussusception in infants and young children?

A

Contrast enemas

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9
Q

What should be considered in the differential diagnosis of focal colitis of the splenic flexure or rectosigmoid colon?

Why?

A
  • Ischemic disease
  • These areas are watershed zonesi
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10
Q

What are the 2 phases of intestinal response to ischemia?

Which phase does the greatest amt. of damage occur in?

A

1) Hypoxic injury: onset of vascular compromise; not much damage occurs in this phase; epithelial cells of gut resistant to injury
2) Reperfusion injury: time when the greatest amt. of damage occurs and in severe cases may trigger multiorgan failure

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11
Q

Where are the watershed zones of the intestines and blood supply ending at each?

A
  • Splenic flexure: SMA and IMA terminate
  • Sigmoid and Colon: IMA, pudendal, and iliac as. end
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12
Q

How does the route of intestinal capillaries running along glands from crypt to surface epithelium play a role in the pattern of atrophy and necrosis seen with ischemic intestinal disease?

A
  • Surface epithelium is particularly vulnerable
  • Morphological signature = surface epithelial atrophy or necrosis and sloughing w/ normal or hyperproliferative crypts
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13
Q

What are the gross morphological characteristics of GI ischemia especially with transmural infarction?

How does it look after initial insult and then later on?

A
  • Demarcation b/w normal and ischemic bowel is sharply defined
  • Initially congested and dusky to purple-red
  • Later –> bowel wall thickened and rubbery by edema
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14
Q

Within 1-4 days following GI ischemia what type of necrosis is seen and of which layer?

A

Coagulative necrosis of muscularis propria

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15
Q

In both acute and chronic ischemia of the GI, what does bacterial superinfection and entero toxin release induce?

Resembles?

A
  • Induce pseudomembrane formation
  • Resembles C. difficle-associated pseudomembranous colitis
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16
Q

Ischemic disease of the colon is most common in what age group?

A

Age 70+

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17
Q

Acute colonic ischemia typically presents clinically how?

A
  • Sudden onset of cramping
  • LLQ pain
  • Desire to defecate
  • Passage of blood or blood diarrhea
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18
Q

Mortality from acute colonic ischemia is doubled in patients with what type of presentation?

Why?

A
  • Right-sided colonic disease
  • Since right side of colon is supplied by SMA, which also supplies much of the small intestine
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19
Q

Other than right-sided involvment in acute colonic ischemia what are other poor prognostic indicators?

A
  • Co-existing COPD
  • Persistence of sx’s for >2 weeks
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20
Q

Intermittent blood diarrhea + intestinal obstruction are most often seen in what type of GI infarction?

A

Mucosal and mural infarctions

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21
Q

Which virus may cause ischemic GI disease due to viral tropism for endothelial cells?

A

CMV

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22
Q

Beyond clinical hx, histologically speaking, the presence of what may provide an important clue to the etiology of radiation enterocolitis?

A

Presence of highly atypical “radiation fibroblasts” within stroma

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23
Q

What are the sx’s of acute radiation enteritis?

A
  • Anorexia
  • Abdominal cramps
  • Malabsorptive diarrhea
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24
Q

What is the most common acquired GI emergency of neonates, particularly premature or low-birth weight infants?

When does it typically manifest?

A
  • Necrotizing enterocolitis (NEC) –> transmural necrosis
  • Presents when oral feeding is initiated
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25
Q

Lesions characterized by malformed submucosal and mucosal blood vessels, occurring most often in the cecum or right colon, during the sixth decade of life is known as?

A

Angiodysplasia

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26
Q

Angiodysplasia is a significant cause of what?

A

Major episodes of lower intestinal bleeding

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27
Q

Which 4 diseases are associated with a defect in intraluminal digestion?

A

1) Chronic pancreatitis
2) Cystic Fibrosis
3) Primary bile acid malabsorption
4) IBD

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28
Q

Painful, bloody, small-volume diarrhea is known as?

A

Dysentery

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29
Q

Differentiate the 4 categories of diarrhea: Secretory diarrhea, Osmotic diarrhea, Malabsorptive diarrhea, and Exudative diarrhea.

Which persist and are relieved by fasting?

A

1) Secretory: isotonic stool and persists during fasting
2) Osmotic: like which occurs w/ lactase deficiency; excess osmotic forces due to unabsorbed luminal solutes; relieved w/ fasting
3) Malabsorptive: follows gen. failure of nutrient absorption; assoc. w/ steatorrhea and is relieved by fasting
4) Exudative: due to inflammatory disease; characterized by purulent, blood stools that continue during fasting

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30
Q

What type of diarrhea is associated with CF?

A

Malabsorptive due to exocrine pancreatic insufficiency

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31
Q

Explain the pathogenesis of Celiac Disease starting with the undigested α-gliadin peptide until deposit of gliadin in the damaged epithelium.

A
  • Gliadn induces epithlial cell expression of IL-15 –> triggers activation/proliferation of CD8+ lymphocytes
  • CD8+ cells express NKG2D (receptor for MIC-A)
  • Stressed enterocytesexpressMIC-Aand are attacked byCD8+ cells
  • Gliadin deposits in damaged epithelium and are deaminated by tissue transglutaminase (tTG)
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32
Q

Deamidated gliadin peptides in the damaged epithelium interact with what on APC’s?

Leads to?

A
  • Interact w/ HLA-DQ2 or DQ-8 on APC’s
  • Stimulates CD4+ T cells to produce cytokines which contribute to tissue damage
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33
Q

What is the histopathology of celiac disease characterized by?

Which cells are seen in increased numbers?

A
  • Increased CD8+ T cells (intraepithelial lymphocytosis)
  • Crypt hyperplasia –> high rate of epithelial turnover –> lack of differentiation
  • Villous atrophy
  • Increased # of plasma cells, eosinophils, and mast cells
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34
Q

What is a sensitive marker for Celiac Disease even in the absence of villous atrophy and epithelial damage?

What combo is most specific for diagnosis?

A
  • Increased # of intraepithelial lymphocytes, particularly within villus
  • Combo of histology + serology is most specific for diagnosis
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35
Q

Between what ages does Celiac Disease most commonly present?

A

30-60 yo

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36
Q

Many cases of Celiac Disease are often asymptomatic and clinical symptoms don’t become evident until the development of what?

A

Anemia due to chronic iron and vitamin malabsorption

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37
Q

Which sex is Celiac disease detected 2x as frequently in and what may be a contributing factor?

A
  • Females
  • Monthly menstrual bleeding –> accentuating the effect of impaired absorption
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38
Q

Which characteristic rash is seen in some patients with Celiac Disease?

Cause?

A
  • Dermatitis Herpetiformis –> itchy, blistering skin lesion
  • IgA deposition @ tips of dermal papillae –> herpes-like blister
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39
Q

What are the 2 most sensitive serologic tests for Celiac disease?

A
  • IgA anti-tTG Abs
  • IgA anti-endomysial Abs
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40
Q

Which malignancies are most common in patients w/ Celiacs Disease?

A
  • Enteropathy associated T-cell lymphoma (most common)
  • Small intestinal adenocarcinoma
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41
Q

When a patient with Celiac disease is following a gluten-free diet but is still experiencing symptoms of weight-loss, abdominal pain, and diarrhea, what differential diagnoses must be considered?

A
  • Cancer
  • Refractory sprue
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42
Q

What is Enviornmental Enteropathy also known as?

Where is it most commonly seen?

A
  • Tropical sprue
  • Populations w/ poor sanitation and hygiene: sub-Saharan Africa, aboriginal populations, some groups of S. America and Asia, India, and Pakistan
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43
Q

What are some of the common signs and symptoms of pts with Tropical Sprue?

A
  • Malabsorption/malnutrition
  • Stunted growth
  • Defective intestinal mucosal immune function
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44
Q

The cause of Tropical Sprue isn’t known, but what are some of the likely involved factors?

A
  • Defective intestinal barrier function
  • Chronic exposure to fecal pathogens
  • Repeat bouts of diarrhea within the first 2 or 3 years of life
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45
Q

What is the inheritance pattern of Autoimmune Enteropathy?

A

X-linked

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46
Q

Autoimmune enteropathy is chararcterized by what (sx’s) and occurs at what age?

A
  • Severe persistent diarrhea and autoimmune disease
  • Occurs most often in children
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47
Q

A particularly severe familial form of Autoimmune Enteropathy is known as?

What is the underlying genetic defect?

A
  • IPEX - immune dysregulation Polyendocrinopathy, Enteropthy, and X-linkage
  • Germline mutation of FOXP3 gene expressed by CD4+ Treg cells
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48
Q

Autoantibodies to what are often seen in Autoimmune Enteropathy?

A
  • Auto-abs to enterocytes/goblet cells
  • Auto-abs to parietal cells/islet cells
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49
Q

What is the treatment for Autoimmune Enteropathy?

A
  • Immunosuppressive drugs: Cyclosporine
  • Rare cases: HSC transplant
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50
Q

What is the inheritance pattern of congenital lactase deficiency?

A

Autosomal Recessive

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51
Q

What are the sx’s of congenital lactase deficiency?

A
  • Osmotic diarrhea: explosive w/ watery, frothy stools
  • Abdominal distention
  • All upon milk ingestion
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52
Q

What is the cause of acquired lactase deficiency?

Particularly common in what populations?

Can develop after what?

A
  • Down-regulation of lactase gene expression
  • Common in Native Americans, Blacks, and Chinese
  • Can develop following enteric viral or bacterial infections
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53
Q

What is the inheritance pattern of Abetalipoproteinemia?

A

Autosomal Recessive

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54
Q

Which mutation is seen in Abetalipoproteinemia?

A

Mutation in microsomal triglyceride transfer protein (MTP)

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55
Q

What is the defect caused by the mutation in Abetalipoproteinemia?

A
  • Without MTP, enterocytes cannot assemble or export lipoproteins, especially ApoB
  • Results in intracellular accumulation of lipids
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56
Q

What is seen histologically in Abetalipoproteinemia?

Stained how?

A
  • Vacuolization of small intestinal epithelial cells
  • Stains such as oil red-O, particularly after fatty meal
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57
Q

When is the onset of Abetalipoproteinemia and what are the signs/symptoms?

What is seen serologically?

A
  • Presents in infancy
  • Failure to thrive, diarrhea, and steatorrhea
  • Complete absence of plasma ApoB (serology)
  • Failure to absorb fat-soluble vitamins (ADEK)
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58
Q

Failure to absorb essential FA’s in Abetalipoproteinemia leads to deficiencies of fat-soluble vitamins as well as lipid membrane defects that can be recognized by the presence of what in peripheral blood smears?

A

Acanthocytic red cells (Burr cells)

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59
Q

What age is the peak prevalance of IBS seen?

Which sex most affected?

A
  • Peak prevalence 20-40 yo
  • Females
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60
Q

Once enteric infection or IBD is excluded, what are the current criteria used for diagnosis IBS

A
  • Abdominal pain at least 3 days/month over 3 months
  • Improvement of sx’s w/ defecation
  • Change in stool frequency or form
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61
Q

What has been identified as one cause of diarrhea-predominant IBS?

A

Excess bile acid synthesis or bile acid malabsorption

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62
Q

How does the location and morphological expression of Ulcerative Colitis differ from that of Chron Disease?

A
  • Ulcerative colitis: limited to colon and rectum; extends only into the mucosa and submucosa
  • Chron disease: may involve any area of GI (Ileum ± colon) and typically transmural
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63
Q

When does IBD (Chron and UC) typically present?

More prevalent in which population?

A
  • Teens and early 20’s
  • Eastern European Ashkenazi Jews (3-5x)
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64
Q

Mutation of which gene is most strongly associated with Chron disease?

What are some of the other implicated genes?

A
  • NOD2 - encodes proteins that bind bacteria peptidoglycan and activate NF-kB path
  • ATG16L1 = part of autophagy path
  • IRGM = part of autophagy path

*All involved in recognition and response to intracellular pathogens

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65
Q

Which T helper cell response is polarized in Chron Disease?

A

TH1

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66
Q

AR mutations in which cytokine and receptor genes are linked to severe, early onset IBD?

A

IL-10 and the IL-10 receptor

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67
Q

Which epithelial defect is associated with Chron Disease?

A

Defects in intestinal epithelial TIGHT JUNCTION barrier

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68
Q

Which polymorphisms associated with epithelial barrier defects have been implicated in ulcerative colitis?

A
  • ECM1 protein polymorphism —> typically inhibits MM9
  • HNFA transcription factor polymorphisms
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69
Q

What type of lesions are characteristic of Chron Disease and can help differentiate it from UC?

A

Skip lesions –> multiple, separate, sharply delineated areas of dz

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70
Q

Which inflammatory infiltrate is abundant in Chron Disease, where does it infiltrate, and causes?

A
  • Neutrophils
  • Infiltrate and damage crypts –> Crypt abscesses
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71
Q

What is one of the morphologic hallmarks of Chron Disease?

A

Non-caseating granlomas of the intestinal wall

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72
Q

What are some of the characteristic clinical signs and symptoms of Chron Disease?

A
  • Intermittent attacks of mild diarrhea, fever, abd. pain
  • RLQ pain, fever, bloody diarrhea –> mimicing acute appedicitis/ perf. bowel
  • Periods of active disease + asymptomatic periods
  • Iron-deficiency anemia, Hypoalbuminemia, and Malabsorption (B12 and Bile salts)
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73
Q

Relapsing blood diarrhea, Fistula, Fibrosing Strictures, and Perforations are all common findings in which IBD?

A

Chron Disease

74
Q

What is a strong exogenous risk factor for the development of Chron Disease and in some cases disease onset is associated with the introduction of this factor?

A

Initiation of smoking sometimes associated w/ disease onset

75
Q

What are the ulcers like in Chron Disease vs. UC?

A
  • Chron = DEEP and knife-like - elongated, serpentine
  • UC = SUPERFICIAL and BROAD-based
76
Q

Which 5 extraintestial manifestations are associated with both Chron and UC?

A
  • Migratory polyarthritis
  • Sacroiliitis
  • Primary sclerosis cholangitis
  • Ankylosing spondylitis
  • Uveitis
  • Skin lesions
77
Q

Erythema nodosum and clubbing of the finger nails are associated with what form of IBD and may develop before intestinal disease is recognized?

A

Chron disease

78
Q

How is UC different from Chron disease grossly when viewing the gut wall, serosal surface, and appearance of strictures?

A
  • Mural thickening is NOT present, are thin instead
  • Serosal surface = normal
  • Strictures do NOT occur
79
Q

Toxic megacolon can result from damage to the muscularis propria in which form of IBD?

A

Ulcerative Colitis

80
Q

What are the clinical features (signs and symptoms) of Ulcerative Colitis?

A
  • Relapsing disorder
  • Attacks of blood diarrhea w/ stringy, mucoid material
  • Lower abd. pain and cramps –> temporarily relieved w/ pooping
81
Q

Grossly, ulcerative colitis always involves which part of the colon?

A

Rectum

82
Q

Isolating islands of regenerating mucosa bulging into the intestinal lumen, creating pseudopolyps, is characterisitc of which form of IBD?

A

Ulcerative Colitis

83
Q

Does surgery (colectomy) cure UC?

A

Yes, but extraintestinal manifestations may persist

84
Q

In contrast to Chron, what is the effect of smoking cessation and smoking on UC?

A
  • Initial onset of sx’s of UC may occur shortly after smoking cessation
  • Smoking may partially relieve symptoms!

*In Chron disease, smoking is linked to the onset of disease and quiting smoking does not produce remission!

85
Q

What is the location of Indeterminate Colitis?

A

Colon only (does not involve small bowel) and in continous pattern

86
Q

Cobblestone mucosa, creeping fat, and strictures are associated w/ what form of IBD?

A

Chron disease

87
Q

Which factors are associated with dysplasia and possible development of neoplasia in patients with Ulcerative Colitis and Colonic Chron Disease?

A
  1. Duration of disease: risk increases sharply 8-10 y after dz onset
  2. Extent of disease: pts w/ pancolitis are at greater risk
  3. Nature of inflammatory response: greater frequency and severity of active inflammatio (presence of neutrophils) = increased risk
88
Q

Patients with IBD and which extraintestinal manifestation of the disease have a greatly increased risk of developing cancer and are generally enrolled for surveillance at the time of diagnosis?

A

Primary sclerosing cholangitis

89
Q

What is the most striking feature of Diversion Colitis?

A

Development of numerous mucosal lymphoid follicles

90
Q

What is the most common histological finding in GVHD affecting the small bowel and colon?

A

Epithelial apoptosis paticularly of crypt cells

91
Q

Creation of a temporary or permanent ostomy and blind distal segment of colon, from which normal fecal flow is diverted may lead to development of what type of colitis?

A

Diversion Colitis

92
Q

Acquired pseudo-diverticular outpouchings of the colonic mucosa and submucosa is known as?

When diverticular are multiple is known as?

A
  • Diverticular disease
  • Diverticulosis = multiple
93
Q

What are some of the factors contributing to the pathogenesis of Colonic diverticula?

A
  • Increased intraluminal pressure in sigmoid colon + unique structure of muscularis propria in colon
  • Exaggerated peristaltic contractions w/ spasmodic sequestration of bowel segments
  • Diets low in fiber –> reduce stool volume, especially in sigmoid = enhances these risk factors
94
Q

Small, flask-like outpouchings, that occur in regular distribution alongside the taeniae coli and most often in the sigmoid colon are characteristic of?

A

Colonic diverticula

95
Q

Which layer is totally absent in colonic diverticula?

A

Muscularis propria

96
Q

Often times asymptomatic, but in subset of pts diverticular disease can producie what symptoms and clinical manifestations?

A
  • Intermittent cramps, lower abd. discomfort, constipation, distention, or sensation of never being able to fully empty rectum
  • Alternating constipation + diarrhea = mimics IBS
  • Occasionally minimal chronic or intermittent blood loss –> visible in stool
97
Q

What is a sessile polyp vs. pedunculated polyp?

A
  • Sessile = small elevation of mucosa (first stage)
  • Pedunculated = polyp w/ a stalk
98
Q

What is the mean age of presentation for Juvenile Polyposis?

A

<5 years old

99
Q

What are the most common mutated genes/pathways in Juvenile Polyposis?

Which gene mutation is most common?

A
  • SMAD4 = most common mutation!
  • BMPR1A
  • TGF-β signaling pathway
100
Q

Syndromic Juvenile Polyps have which inheritance pattern?

A

Autosomal Dominant

101
Q

Where are most juvenile polyps located and associated symptoms?

Associated complications?

A
  • In the rectum –> present w/ rectal bleeding
  • Complications = intussusception, intestinal obstruction, or polyp prolapse (through anal sphincter)
102
Q

What are some of the recognized extraintestinal manifestations of juvenile polyps?

A
  • Pulmonary arteriovenois malformations
  • Digital clubbing
  • Congenital malformation (i.e., polydactyly)
103
Q

What are the risks of dysplasia in the sporadic vs. syndromic-type of juvenile polyps?

Which cancer may be manifested later in life?

A
  • Sporadic = extremely rare
  • Syndromic = high risk for dysplasia –> Colonic adenocarcinoma by age 45
104
Q

What is the inheritance pattern of Peutz-Jeghers Syndrome?

A

Autosomal Dominant

105
Q

What is the median age of presentation for Peutz-Jeghers Syndrome?

How does it present?

A
  • Age 11
  • Multiple GI hamartomatous polyps + Mucocutaneous hyperpigmentation (i.e., freckles)
106
Q

The mucocutaneous hyperpigmentation associated w/ Peutz-Jeghers syndrome is similar to freckles, but how is it distinguised?

A

Presence on the buccal mucosa

107
Q

Pts with Peutz-Jeghers Syndrome have a markedly increased risk of several malignancies, which malignancies are most common at birth, late childhood, and 2nd-3rd decades of life?

A
  • Birth = sex cord tumors of testes
  • Late childhood = gastric and small intestinal cancers
  • 2nd-3rd decades = colon, pancreatic, breast, lung, ovarian, and uterine cancers
108
Q

Which gene mutation/pathways is most often present in patients w/ Peutz-Jeghers Syndrome?

A
  • Loss-of-function (both alleles) of STK11 (tumor suppressor)
  • Causes loss of AMP kinase-related pathways regulating cell polarization and acting as a brake on growth/anabolic metabolism
109
Q

Where do polyps of Peutz-Jeghers syndrome typically occur?

A

Small intestine

110
Q

What is the distinguishing morphological characteristics of Peutz-Jeghers polyps, which can be helpful in differentiating from those of Juvenile Polyps?

A

ARBORIZING network of CT and SMOOTH muscle intermixed w/ lamina propria

111
Q

What are the morphological characteristics of Juvenile Polyps?

A
  • Pedunculated, smooth-surfaced, reddish lesions w/ dilated cystic spaces
  • Remainder composed of lamina propria expanded by mixed inflammatory infiltrates
112
Q

Which 3 factors/findings are critical for the diagnosis of Peutz-Jeghers syndrome?

A
  • Multiple polyps in the small intestine
  • Mucocutaneous hyperpigmentation
  • Postive family hx
113
Q

What are the most common neoplastic polyps?

Precursors to the majority of which type of cancer?

A
  • Colonic adenomas
  • Precursors to the majority of colorectal adenocarcinomas
114
Q

What is the frequency of colonic adenomas in the Western World and by what age?

A

30% of adults by age 60

115
Q

In regards to colonic adenomas, what is the most important characteristic that correlates with malignancy?

A

Size

I.e., cancer extremely rare in adenomas <1 cm, but 40% lesions >4 cm contain foci of cancer

116
Q

Familial adenomatous polyposis (FAP) is caused by what gene mutation and this gene is a key negative regulator of which signaling pathway?

A
  • APC
  • Wnt signaling pathway
117
Q

If FAP is left untreated there is a 100% chance of developing what?

Often by what age?

A
  • Colorectal adenocarcinoma
  • Often before age 30 and nearly always by age 50
118
Q

Which extraintestinal manifestation associated with FAP can generally be detected at birth and therefore may be an adjunct to early screening?

A

Congenital hypertrophy of the retinal pigment epithelium

*Can also be seen in attenuated FAP but won’t present until age 40-50

119
Q

Some FAP patients without APC loss may have bi-allelic mutations of which gene and the what is the function of this gene normally?

When present this disorder is called?

A
  • MYH –> base-excision repair gene
  • MYH-associated polyposis
120
Q

What is the inheritance pattern of MYH-associated (aka MUTYH-associated) polyposis?

A

Autosomal recessive

121
Q

How is MYH-associated polyposis (aka MUTYH-associated) different from FAP?

A
  • Similar to the attenuated version
  • Polyps develop LATER (age 30-50) w/ FEWER than 100 adenomas and delayed appearance of colon cancer, often at ages 50 or older

*FAP must have at least 100 polyps and can often have 1000’si

122
Q

Which other mutation and type of polyp is also frequently present in the MYH-associated (aka MUTYH-associated) polyposis?

A

Serrated polyps, often w/ KRAS mutations

123
Q

What is the inheritance pattern of Hereditary Non-Polyposis Colorectal Cancer (aka Lynch Syndrome)?

A

Autosomal Dominant

124
Q

Which genes are most frequently mutated and lead to HNPCC (aka Lynch syndrome)?

Normal function of these genes?

A
  • MSH2 or MLH1
  • Encode proteins responsible for detection, excision, and repair of errors that occur during DNA replication
125
Q

MYH-associated polyposis characteristically has what type of adenomas?

Which type of adenocarcinoma is common (typical or mucinous)?

A
  • Sessile serrated adenoma
  • Mucinous adenocarcinoma
126
Q

With loss of both copies of the gene associated with HNPCC, mutations accumulate at rates up to 1000x higher than normal, most often in what regions = most frequent sites of mutations?

A

Microsatellites —> Microsatellite instability

127
Q

What age range is typical for the classic-type FAP?

A

10-15 yo

128
Q

What age range is typical for the attenuated-type FAP?

A

40-50 yo

129
Q

Which subtype of FAP is associated w/ Osteomas, Thyroid and Desmoid Tumors, and Skin Cysts?

Normally presents between what ages?

A
  • Gardner syndrome
  • Presents between 10-15 yo
130
Q

Which subtype of FAP is associated w/ Medulloblastoma and Glioblastomas?

Typically presents during which ages?

A
  • Turcot syndrome
  • Ages 10-15 yo
131
Q

Which disease is associated w/ hamartomatous polyps of the stomach, small intestine, or colon and has extraintestinal manifestations including nail atrophy, hair loss, abnormal skin pigmentation, cachexia and anemia?

What is the mean age of presentation?

A
  • Cronkhite-Canada syndrome
  • Age = >50 yo
132
Q

What are some of the main differences between the colon cancers seen in HNPCC vs. sporadic colon cancers?

A
  • HNPCC tends to occur at a younger age; located in right side of colon
  • Majority of sporadic CC arises on the left side, but some variants can arise on right
133
Q

What is the morphology of typical adenomas?

A
  • Pedunculated or sessile
  • Surface resembling velvet or raspberry texture
134
Q

What are the distinguishing characteristics of epithelial dysplasia most easily appreciated at the surface of an adenoma?

A
  • Prominent nucleoli
  • Eosinophilic cytoplasm
  • Reduction in # of goblet cells
135
Q

What type of adenoma is this; what are the distinguishing features?

A
  • Sessile serrated adenoma
  • Serrated architecture, cyrpt dilation, and lateral growth
136
Q

What is the normal histo features of the adenoma that arises from FAP?

What type of adenocarcinoma (typical or mucinous)?

A
  • Tubular or Villous appearing adenoma
  • Typical adenocarcinoma

*Image on left = tubular, image on right = villous

137
Q

Which type of adenocarcinoma arises in HNPCC (typical or mucinous)?

Typical adenoma seen?

A
  • Mucinous adenocarcinoma on right side
  • Sessile Serrated adenoma
138
Q

Colorectal adenocarcinomas have the highest incidence in which geographical location?

A

North America

139
Q

Colorectal cancer incidence peaks at which age?

A

60-70 years old

140
Q

Several epidemiologic studies have shown that which pharmacologic agent may have a protective effect against colorectal carcinomas?

A
  • NSAIDs, which inhibit COX-2
  • COX-2 is highly expressed in these cancers
141
Q

Which gene/pathway mutation accounts for the majority of sporadic colonic adenocarcinoma?

Describe the normal role of this gene and the pathway it regulates.

A
  • APC/ β​-catenin (BOTH copies of APC must be inactivated)
  • APC is key negative regulator of β-catenin, a component of the Wnt signaling pathway
142
Q

What is the most common epigenetic event associated w/ the progression of colonic adenocarcinoma?

A

Methylation-induced gene silencing

143
Q

As neoplastic progression of colonic adenocarcinomas continues what additional mutations may be acquired along the way?

A
  • Activating mutations of KRAS
  • -* Mutations in SMAD2 and SMAD4 –> TGF-β signaling
  • Loss of function ofTP53
144
Q

In colonic adenocarcinomas, tumor suppressor genes may be silenced by methylation of which 2 regions?

A
  • CpG-rich zone
  • CpG island
145
Q

Which chromosome is APC, KRAS, and TP53 located on?

A
  • APC —> Cr. 5
  • KRAS –> Cr. 12
  • TP53 –> Cr. 17
146
Q

In the sporadic-type of colonic adenocarcinoma involving the APC/WNT pathway, what type of adenoma is seen?

What type of adenocarcinoma (typical or mucinous) and is seen usually on what side of colon?

A
  • Tubular, villous adenomas
  • Typical adenocarcinoma on the LEFT side
147
Q

Other than the APC/WNT mutations some sporadic colonic adenocarcinomas are associated with defects in what?

This accumulation of mutations is referred to as?

A
  • Defects in DNA mismatch repair
  • Microsatellite instability
148
Q

In cases of microsatellite instability-associated colonic adenocarcinomas, genes that encode what components are often mutated?

A
  • mutated type II TGF-β receptor (typically regulates eipthelial cell growth) –> uncontrolled cell growth
  • loss of pro-apoptotic protein BAX –> enhanced survival
149
Q

A subset of microsatellite unstable colon cancers without mutations in DNA mismatch repair enzymes demonstrates which CpG island hypermethylated phenotype?

What is the signature of this pathway of carcinogenesis?

A
  • MLH1 promoter is hypermethylated
  • Activating mutations in BRAF
  • Signature of this pathway = microsatellite instability + BRAF mutation + methylation of MLH1
150
Q

Colonic adenocarcinomas with mutations in DNA mismatch repair (MSH2, MLH1) or with microsatellite instabilities are commonly associated with what type of adenoma?

Produce what type of adenocarcinoma (typical or mucinous)?

On what side?

A
  • Sessile serrated adenomas
  • Mucionous adenocarcinoma
  • RIGHT side
151
Q

Polypoid, exophytic masses that extend along one wall of the large-caliber cecum and ascending colon, rarely causing obstruction, describes what type of adenocarcinoma (i.e., location)?

A

Adenocarcinoma of the proximal colon

152
Q

In contrast to tumors of the proximal colon, what are the characteristic morphologies of adenocarinomas in the distal colon?

i.e., type of lesions, constriction or not, narrowing/thickening, obstructions?

A
  • Annular lesions
  • Produce “napkin ring” constrictions
  • Luminal narrowing –> sometimes obstruction
153
Q

Microscopically, what cells and morphology of these cells is seen in colonic adenocarcinomas?

A

Tall columnar cells that resemble dysplastic epithelium

154
Q

Colonic adenocarcinomas that produce which substance are associated with poor prognosis?

A

Mucin

155
Q

Which symptoms are generally what call clinical attention to the presence of cecal and other right-sided colon cancers?

A

Fatigue and weakness due to iron deficiency anemia

156
Q

Which symptoms are generally what call clinical attention to the presence of left-sided colon cancers?

A
  • Occult bleeding
  • Changes in bowel habits
  • Cramping
  • LLQ discomfort
157
Q

What are the 2 most important prognostic factors for colonic adenocarcinomas?

A
  1. Depth of invasion
  2. Presence of LN metastases
158
Q

What is the most common site and other sites of metastases by colonic adenocarcinomas?

A
  • Liver = MOST common
  • Regional LNs
  • Bone
  • Lungs
159
Q

The anal canal is divided into thirds, what type of cells are found in the upper, middle, and lower 1/3?

A

Upper = columnar rectal epithelium

Middle = transitional epithelium

Lower = stratified squamous epithelium

*From top to bottom; ‘C’ comes before ‘S’

160
Q

In the anal canal, when the entire tumor displays a basaloid pattern, which term is used to describe the tumor?

A

Cloacogenic carcinoma

161
Q

Pure squamous cell carcinoma of the anal canal is frequently assoicated with what type of viral infection?

Which characteristic precursor lesions may this infection produce?

A
  • HPV infections
  • Precursor lesions = condyloma acuminatum
162
Q

Hemorrhoids are associated with what predisposing influences?

A
  • Straining at defecation
  • Constipation
  • Venous stasis of pregnancy
  • Portal HTN
163
Q

What is the initiating event in the development of appendicitis?

A

Progressive increases in intraluminal pressure that compromise venous outfow

164
Q

Diagnosis of acute appendicitis requires what morphological finding?

A

Neutrophilic infiltration of the muscularis propria

165
Q

What is the most common tumor of the appendix?\

Benign or malignant?

A
  • Well-differentiated neuroendocrine (carcinoid) tumor
  • Typically benign
166
Q

What type of adenoma and tumor may be seen in the appendix and can enlarge/cause obstruction that mimics appendicitis?

A

Conventional adenomas or non-mucin producing adenocarcinomas

167
Q

A dilated appendix filled with mucin is called what?

May also be a consequence of what type of adenoma or tumor?

A
  • Mucocele
  • Mucinous cystadenoma or Mucinous cystadenocarcinoma
168
Q

Mucinous cystadenocarcinomas of the appendix can invade the wall and lead to intraperitoneal seeding and spread, and in some advanced cases the abdomen fills with what?

This condition is called?

A
  • Abdomen fills with tenacious, semisolid mucin
  • Pseudomyxoma peritonei = disseminated intraperitoneal disease
169
Q

What is sterile peritonitis due to?

A

Leakage of bile or pancreatic enzymes

170
Q

Perforation or rupture of the biliary system evokes what type of peritonitis; may lead to?

A
  • Highly irritating peritonitis
  • Bacterial superinfection
171
Q

Which cause of peritonitis is associated with leakage of pancreatic enzymes and fat necrosis?

A

Acute hemorrhagic pancreatitis

172
Q

What is released into the peritoneum with a rupture dermoid cyst and what type of rxn ensues?

A
  • Keratin is released
  • Intense granulomatous rxn
173
Q

What are the 5 most common organisms associated with bacterial peritonitis?

A
  • E. coli
  • Streptococci
  • S. aureus
  • Enterococci
  • C. perfingens
174
Q

Which 2 underlying conditions are most commonly associated with spontaneous bacterial peritonitis?

A
  • Cirrhosis
  • Ascites
175
Q

Sclerosis retroperitonitis (aka idiopathic retroperitoneal fibrosis or Ormond disease) is characterized by what findings?

Thought to be related to what?

What is frequently compressed in this disorder?

A
  • Dense fibrosis that may extend to involve the mesentery
  • Spectrum of IgG4-related sclerosis disease, an autoinflammatory disorder
  • Ureters are frequently compressed!
176
Q

Primary malignant tumors of the peritoneal cavity arise from the peritoneal lining and are called?

Almost always associated with what risk factor?

A
  • Mesotheliomas (similar to tumors of the pleura and pericardium)
  • Asbestos exposure
177
Q

Although rare, what is the most common malignant soft-tissue tumors of the peritoneum and retroperitoneum?

Usually seen in whom?

A
  • Desmoplastic small round cell tumor
  • Children and young adults (resembles Ewing Sarcoma)
178
Q

What type of translocation and fusion gene product is associated with desmoplastic small round cell tumors of the peritoneum?

A
  • t(11;12)
  • Fusion of EWS and WT1 genes
179
Q

Mucinous carcinomas, particularly of the appendix may cause what in the peritoneum?

A

Pseudomyxoma peritonei

180
Q

Secondary tumors of the peritoneum from direct spread or metastatic seeding are called what?

A

Peritoneal carcinomatosis

2020 GI II Exam 1 (13 decks)

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