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First Aid: GI Path


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What is Achalasia?
Failure of relaxation of lower the lower esophageal sphincter due to loss of myenteric (Auerbach's) plexus.
Clinical manifestations of Achalasia
Progressive dysphagia

Barrium swallow shows dilated esophagus with an area of distal stenosis; "bird beak" on barium swallow
Achalasia is associated with what other syndromes?
associated with an increased risk of esophageal carcinoma

secondary achalasia may arise from Chagas disease
Barret's Esophagus
Glandular (columnar epithelial) metaplasia - replacement of nonkeratinized squamous epithelium with gastric (columnar)epithelium in the distal esophagus
Where does Barrets Esophagus arise?
from the stomach --> lower Esophageal sphincter extending upward
What does Barret's result from and what does it become?
BARRett's = Becomes Adenocarcinoma, Results from Reflux
What are the Risk factors for Esophageal Carcinoma?
Barrest's Esophagus
Diverticuli (e.g Zenkers Diverticulum)
Esophageal Web
most comon type of esophageal Carcinoma
Squamous Cell

Barrett's causes Adenocarcinoma
Congenital Pyloric Stenosis
Hypertrophy of the pylorus causes obstruction
Who does Pyloric stenosis affect?
infants ~ 2 weeks of age
What findings are associated with congenital pyloric stenosis?
palpable mass int eh epigastric region and projectile vomiting
Celiac Sprue results from?
Antibodies to gluten (anti-gliadin) in wheat and other grains
Findings associated with Celiac Sprue
Villus flattening and lymphocytic infiltrate

Antigliadin, antiendomysial, and anti-tissue transglutaminase antibodies
Characteristics of Tropical Sprue
probably infectious

responds to antibiotics
Whipple's disease
Infection with Tropheryma whippelii

PAS-positive macrophages
Disaccharidase deficiency
most commmon in lactase deficiency --> milk intolerance

large volume stools (osmotic diarrhea) and flatus
Pancreatic Insufficiency
Due to Cystic fibrosis or chronic pancreatitis

Causes malabsorption of protein, fat, vitamins A,D,E,K.
Celiac Sprue, Whipples dz, Disaccharidase def., Pancreatic Insufficiency are all examples of...?
Malabsorptive syndromes
Distinguish between Type A and Type B Chronic gastritis.
Type A = 4 A's
Autoimmune disorder characterized by Autoantibodies to pareital cells, pernicious Anemia, and Achlorhydria

Type B = a Bug, caused by H.pylori infection

Both carry increased risk of gastric carcinoma
Gastric Ulcer DZ
Pain Greater with meals --> weight loss
H.pylori Infection in 70% cases; NSAID use also implicated
due to DEC. mucosal protection against gastric acid
Duodenal Ulcer DZ
Pain Decreases with meals --> wieght gain
Almost 100% have H.pylori infection
Due to INC gastric acid secretion or DEC mucosal protection
Hypertrophy of Brunner's glands
What is the morphological appearance of Duodenal ulcers?
Tend to have clean, "punched out" margins unlike the raised/ irregular margins of carcinoma.
Complications of Duodenal ulcer dz. Who is at INC risk for DU dz?
bleeding, penetration, perforation, and obstruction (not intrinsically precancerous)

incidence of peptic ulcer dz is twice as great in smokers
How are duodenal ulcers treated?
H.pylori infection can be treated with "triple therapy" (metronidazole, bismuth salicylate, and iether amoxicillin or tetracycline) with or without a proton pump inhibitor
Crohn's Disease:

1. Etiology

2. Location

3. Complications
1. Infectious

2. May involve the entire GI tract but it is most common in the terminal iluem, followed small intestine, and colon. Skip lesions, rectal sparing

3. Stricures, fistulas, perianal disease, malabsorption - nutritional depletion
Ulcerative Colitis:

1. Etiology

2. Location

3. Complications
1. Autoimmune

2. Colitis = colon inflammation, continuous lesions of the colon with rectal involvement

3. Severe Stenosis, toxci megacolon, colorectal carcinoma
Crohn's Disease:

1. Gross Morphology
2. Microscopic Morphology
3. Extraintestinal Manisfestations
1. Transmural inflammation. Cobblestone mucosa, creeping fat, bowel wall thickening ("string sign" on x-ray), linear ulcers, fissures

2. noncaseating granulomas

3. migratory polyarthritis, erythema nodosa

*fat old crone skipping down a cobblestone road!
Ulcerative Colitis:

1. Gross Morphology
2. Microscopic Morphology
3. Extraintestinal Manisfestations
1. mucosal inflammation. friable mucosal pseudopolyps with freely hanging mesentery

2. crypt abscesses and ulcers

3. pyoderma gangrenous, sclerosing cholangitis
most common indication for emergent abdominal surgery in children

affects all age groups
What are the clinical manisfestations of Appendicitis?
initial diffues periumbilical pain --> localized pain at McBurney's point.

Nausea fever; may perforate --> peritonitis
what are differential diagnoses of appendicitis?
diverticulitis (in elderly)

ectopic pregnacy (use B-hCG to rule out)
What is a diverticulum?
blind puch leading off the alimentary tract, lined by mucosa, muscularis, and serosa, that communicates with the lumen gut.

Most diverticula are acquired and termed "false" becasue they have an attenuated muscularis propia or lack one completely
What causes diverticulosis?
INC intraluminal pressure and focal weakness in the colonic wall.

most frequently involve the sigmoid colon, and associated with a low fiber diet
Clinical manifestations of Diverticulosis?
prevelance in patients >60 is almost 50%

most often asymptomatic or associatd with vague discomfort
DWhat is diverticulitis?
Inflammation of diverticula classically causing LLQ pain

may be complicated by peritonitis, perforation, abcess formation, or bowel stenosis.

affects elderly patients
What is Intussusception?
telescoping of 1 bowel segmetn into distal segment; can comprimise blood supply
What is volvulus?
twisting of portion of bowel around its mesentary; can lead to obstruction
Patholgy and clinical manifestations of Stomach Cancer?
almost always Adenocarcinoma. Early aggressive local spread and node/liver metastasis

Associated with dietary nitrosamines, achlorhydria, and chronic gastritis.

Termed linitis plastica when it is diffusely infiltrative (thickened, rigid appearance)
what is a Virchow's node?
involvement of supraclavicular node by metastasis from the stomach
what is a Krukenburg's tumor?
bilateral metastasis of GI cancer (us. stomach) to the ovaries

histo shows abundant mucus and signet ring cells

speads hematogenously
What is Hirschsprung's disease?
congenital megacolon charcterized by lack of enteric nervous plexus in segment (Auerbach's and Meissner's plexuses) on intestinal biopsy

Due to failure of neural crest cell to migrate down GI
Clinical Manifestations of Hirschsprung's disease?
present as chronic constipation early in life

dilated portion of the colon proximal to the agaonglionic segment resulting in a "transition zone"
Colorectal Cancer Risk Factors
colorectal villous adenomas, chronic inflammatory bowel disease, familial adenamatous polyposis(FAP), hereditary nonpolyposis colorectal cancer (HNPCC)

INC age, low fiber diet, personal and family hx colon cancer

screen patients >50 years old with stool occult blood test, colonoscopy
Is Peutz-Jeghers syndrome a risk factor for colorectal cancer?
NO, it is a BENIGN polyposis syndrome

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