Gastrointestinal Tract Pathology 
| Esophageal Disorders |
Gastric Disorders |
| Intestinal Disorders |
|
Esophagus
Achalasia
A condition of unknown etiology resulting from abnormal function of the
neural plexus coordinating esophageal peristalsis.
Clinical: Progressive dysphagia
Nocturnal regurgitation
Aspiration
Increased risk (5%) for squamous cell carcinoma
Mallory-Weiss Syndrome
Condition primarily seen in chronic alcoholics. Severe retching leads to
tears at the esophagogastric junction.
Clinical: Hematemesis
Fatal in presence of esophageal varices (40% mortality rate)
Hiatal Hernia
This condition increases in frequency with age. Herniation of the stomach
through the hiatal crura typically follows one of two pattterns.
Sliding Hiatal Hernia (95%)
Protrusion of the stomach and lower esophageal sphincter
(LES) above the diaphragm. This pattern is seen in
approximately 1-20% of pop. with about 9% showing
symptoms of reflux.
Rolling (Paraesophageal) Hiatal Hernia
Herniation of a portion of the stomach (Greater Curvature)
through diaphragm alongside esophagus. Rarely develop
reflux but may lead to strangulation/obstruction.
Esophagitis
Inflammation of esophageal mucosa as a result of reflux is seen in 10-20%
of U.S. population. Contributory factors include:
1. Decreased LES function
2. Decreased clearance of reflux material
3. Increased gastric volume
4. Decreased repair capacity of mucosa due to repeated injury
Clinical: Pyrosis (Heartburn)
Regurgitant sour brash
Chest pain
Barrett's Epithelium
Ulceration
Adenocarcinoma
Stomach
Acute Gastritis
Transient inflammation of the gastric mucosa. Typically seen in
conjunction with:
1. Heavy NSAID use
2. Excessive alcohol use
3. Heavy smoking
4. Chemotherapy
5. Severe stress
6. Ischemia/shock
7. Suicide attempts
8. Mechanical trauma (intubation)
The development of acute gastritis is thought to occur secondarily to the
disruption of the stomach's natural defense mechanisms.
Clinical: Asymptomatic
Epigastric pain
Nausea/vomiting
Hematemesis
Melena
Occult bleeding
Chronic Gastritis
Chronic inflammation of gastric mucosa leading to metaplasia and atrophy.
The primary factor is infection with Helicobacter pylori (50% U.S. pop.).
Clinical: Asymptomatic
Epigastric pain
Hematemesis/melena
Peptic Ulcer
Peptic Ulcer
Localized damage of the mucosa and submucosa extending into the
muscularis. The primary site is the proximal duodenum and stomach.
These ulcerations are though to arise from the combined effects of H.
pylori infection (urease and protease release) and direct contact of mucosa
with stomach acid. Note: Only 10-20% of population with
established H.pylori infections develop
ulcers.
Clinical: Epigastric pain
Hemorrhage/perforation
Acute Gastric Ulceration (Stress Ulcers)
Response of the gastric mucosa to severe stress:
Severe Trauma/Grave Illness
Severe Burns (Curling's Ulcers)
CNS Injury (Cushing's Ulcers)
Chronic use of NSAIDS
Chronic Corticosteroids
Clinical: These lesions tend to be a benign response compared to the
primary condition.
Gastric Carcinoma
The major primary cancer of the stomach is adenocarcinoma that presents as
one of two major forms.
Intestinal Type Adenocarcinoma
This form of cancer is decreasing in incidence within the U.S. it is linked
to environmental exposures such as:
1. Nitrites/Nitrates
2. Smoked/Pickled food
3. Excessive salt
4. H. pylori infection
5. Chronic Gastritis
6. Gastrectomy
Diffuse Carcinoma
Form of stomach cancer that has been historically stable. Its risk factors
are undefined without a connection to a history of gastritis or H. pylori
infection. One risk factor has been a statistical link to people with blood
group A expression.
Clinical: Early cancer asymptomatic
Dysphagia
Obstruction
Melena/Occult blood
Krukenberg tumor (spread to ovaries)
Linitis plastica (leather bottle stomach - diffuse wall
penetration)
Intestinal Pathology
Hirschsprung Disease (Congenital Megacolon)
This developmental abnormality (1/6500 births) results from the lack of ganglia
development within the colon wall (Meissner's and Auerbach's plexus).
Interference of peristalsis leads to functional obstruction and dilatation.
Clinical: Delay in meconium passage
Vomiting in neonate
Enterocolitis
Electrolyte imbalance
Perforation
Ischemic Bowel Disease
Infarction of bowel is primarily the result of major vessel occlusion (celiac,
superior, inferior mesenteric arteries). This condition is most often seen in the
elderly with predisposing conditions such as:
1. Major abdominal surgery
2. Myocardial infarct
3. Atrial fibrillation
4. Vegetative endocarditis
5. Severe heart failure
Clinical: Abdominal pain
Bloody diarrhea
Abdominal distention
Gangrene
Course: Medical emergency due to rapid development of gangrene (24 hrs)
with subsequent vascular collapse and shock. Mortality rate 90%.
Diarrhea
This condition is characterized primarily by excessive water loss in the stool (>
200 gm/day). In severe cases over 14 liters of water loss per day. A major
form of diarrhea (infectious enterocolitis) is responsible for 14,000 child
deaths/day on a global basis. The major forms of diarrhea are:
1. Secretory
Viral disease
Enterotoxin (E.coli, cholera)
Excessive laxative use
2. Osmotic
Anatacids
3. Exudative Disease
Shigella, Salmonella
Idiopathic Inflammatory Bowel Disease
4. Malabsorption
5. Deranged Motility
Malabsorption Syndrome
Heterogeneric category of conditions that interfere with normal dietary intestinal
absorption. (* common in U.S.)
1. Defective Intraluminal Absorption
* Pancreatic insufficiency
Zollinger-Ellison syndrome
Bile Flow Interference
* Ileal Resection
2. Primary Mucosal Cell Abnormality
* Lactose Intolerance (Dissacharidase)
3. Reduced Small Intestinal Surface
* Celiac Sprue
* Surgical Resection
* Crohn's Disease
4. Lymphatic Destruction
Lymphoma
5. Infection
Acute infectious enteritis/Parasites
Whipple's disease/Tropical Sprue
6. Iatrogenic
* Gastrectomy
* Ileal resection/Bypass
Clinical:
Bulky, frothy, greasy, yellow stool
Steatorrhea
Weight loss
Anorexia
Borborygmus/Flatus
Systemic Dysfunction
Idiopathic Inflammatory Bowel Disease
A group of disorders with unknown etiology but with characteristics of
abnormal host immunoreactivity. Although often familial, no specific genetic
determinants have been identified.
Inflammation results in:
1. Mucosal epithelial barrier breakdown
2. Loss of epithelial absorptive function
3. Activation of epithelial cell secretion
Crohn's Disease
This is characterized as a systemic disease with primary GI involvement.
Disease typically appears in age 20-30 (1-3/100,000).
Clinical: Transmural Inflammation
Skip Lesions
Regional Enteritis
Cobblestone mucosa
Non-caseating granuloma
Strictures
Fistulas
Diarrhea
Ulcerative Colitis
Inflammatory disease limited to the rectum and colon. This is also a systemic
disorder with primary GI tract involvement.
Clinical: Contiguous inflammation
Mucosal and submucosal inflamm.
Pseudopolyps
Toxic megacolon
Bloody diarrhea
Tenesmus
Adenocarcinoma risk
Colonic Diverticulosis
Diverticula are outpouchings of the alimentary tract. These diverticula have all
of the normal wall components and their lumen connects with the main lumen.
A few diverticula are congenital (Meckel's, Zenker's) but most are acquired.
The colon is the major site for development of acquired diverticula. These
structures arise from:
1. Abnormal intraluminal pressure (spastic peristalsis)
2. Weak points in colon muscle layer (vasa recta)
Clinical: Asymptomatic
Lower abdominal cramps
Minor bleeding
Impaction/perforation
Bowel Obstruction
Intussusception
Telescoping of one segment of bowel into another. Occurs in children
(hyperactive peristalsis) and individuals with intraluminal lesions (tumors).
Arterial and venous compression often leads to bowel segment infarction.
Volvulus
Twisting of a loop of bowel around itself. Occurs more frequently with
advanced age (loosening of omentum). This also leads to bowel
infarction.
Intestinal Tumors
The colon and rectum are the site of more primary tumors than any other organ.
The majority of these tumors are adenocarcinomas (70%) and most are found in
the large intestine and rectum.
Non-Neoplastic Polyps
This group of lesions makes up about 90% of all epithelial intestinal
polyps. These hyperplastic growths are essentially without malignant
potential.
Adenomas
Neoplastic polyps occuring primarily in the colon and increase in
frequency with age (40-50% age > 60). These epithelial dysplasias have
two major growth patterns:
1. Tubular adenoma (>95%)
2. Vilous adenoma (1%)
Tubular adenomas
Lesion has a stalk and head. Within the head is neoplastic tissue.
Vilous adenomas
Large velvety or cauliflower-like lesions. These lesion are often 10 cm. in
diameter.
Clinical: Asymptomatic
Occult bleeding
All are considered potentially malignant
Colorectal Carcinoma
The vast majority (98%) are adenocarcinomas. They represent about 15% of
all cancer deaths. These lesions typically appear around age 60-70. Colorectal
cancer is linked to a number of dietary factors:
1. Low fiber diet
2. High refined carbohydrate diet
3. High fat diet
4. Low vitamin (A,C,E) intake
Clinical: Asymptomatic
Iron deficiency anemia
Occult bleeding
In 25% tumor is unoperable
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