General Pathology 601 for Dental Students

Pathology of The Esophagus and Stomach

Melissa J. Contos, MD
Surgical Pathology/Cytopathology
Gateway Bldg, 6th floor
Office: (804) 828-9739
mjcontos@vcu.edu

Objectives | Terms
Esophagus  | Anatomic disorders | Disorders of Motility | Esophagitis | Neoplasms | Stomach
Chronic Gastritis | Acute Gastritis and Acute (stress) Ulcers | Peptic Ulcers | Gastric Carcinoma

Objectives
Upon completion of this lecture you will be able to:

1. List 3 general symptoms of esophageal disorders.
   
   
2. Name 3 etiologies of esophagitis.
   
   
3. Distinguish between adenocarcinoma and squamous cell carcinoma of the esophagus including risk factors.
   
   
4. Define chronic and acute gastritis.
   
   
5. Discuss the etiology and pathogenesis of chronic gastritis, acute gastritis and peptic ulcers.
   
   
6. Describe 2 morphologic types of gastric carcinoma.
   

Disorders of the esophagus and stomach are very common and thus, are frequently encountered in routine medical practice. The lesions involving these organs range from minor inflammatory conditions that are annoying, but not life threatening, to rapidly progressive neoplasms with a poor prognosis. The symptoms are often vague. The key to medical practice is to be able to discern the benign process and to do it with as few procedures and expenditures as possible.

Esophagus

Disorders of the esophagus can be divided by: 1) pathologic process--anatomic/motility/ inflammatory/vascular/neoplastic--or, can be divided by 2) clinical presentation (i.e., symptoms).

Symptoms of the esophageal disorders include:

1. Upper gastrointestinal bleeding--lacerations, varices
   
   
2. Odynophagia (painful swallowing)--infections, other inflammatory insults
   
   
3. Dysphagia (difficulty swallowing)--disorders of motility (solids and liquids), obstructions such as tumors and benign strictures (solids first, progressing to liquids).

Anatomic Disorders

• Hiatal hernia--1-20% of population; 9% symptomatic (Related to incompetence of lower esophageal sphincter)
  
  
• Type 1 (Sliding)--95%; protrusion of the stomach above the diaphragm creates a bell shaped dilation
  
  
• Type 2 (Paraesophageal)--stomach rolls along side of lower esophageal sphincter (LES), may strangulate or obstruct and thus is often managed surgically.

Esophagitis
Types

1. Corrosive
   
   
2. Infectious--CMV/Herpes/Candida
   
   
3. Reflux
   
   • Severity of symptoms does not correlate with histology
     
     
   • Complications include bleeding, stricture, Barrett's metaplasia (intestinal metaplasia)

Neoplasms
Types

1. Adenocarcinoma
   
   
   • risk--Barrett's
     
     
2. Squamous Cell Carcinoma
   
   
   • risk--alcohol and tobacco abuse, diet, esophagitis, genetics

Stomach

Chronic Gastritis
Chronic gastritis is defined as the presence of chronic mucosal inflammatory changes leading eventually to mucosal atrophy and epithelial metaplasia. Risk of developing intestinal metaplasia, dysplasia and carcinoma.

Helicobacter pylori
The most important etiologic association is infection with this gram negative, urease-producing bacillus that exclusively resides in the mucous layer of gastric-type epithelium. It is associated with: 1) peptic ulcer disease (gastric and duodenal ulcers) 2) gastric carcinoma and 3) gastric lymphoma.

Autoimmune
Rare in US and more common in Scandinavia, autoimmunity results from antibodies to parietal cells, specifically to the H+, K+ - ATPase. The gland destruction results in mucosal atrophy with decreased acid and intrinsic factor production. The lack of acid production increases the PH which signals the gastrin producing cells to release more gastrin. The resulting hypergastrinemia can stimulate neuroendocrine proliferation in the body of the stomach that may lead to carcinoid tumors. The lack of intrinsic factor results in a megaloblastic anemia--pernicious anemia.

Acute Gastritis and Acute (stress) Ulcers
Acute gastritis is defined as an acute mucosal inflammatory process that is usually transient in nature. Overall is one of the major causes of upper gastrointestinal bleeding. Etiologies include NSAIDs, alcohol, uremia, chemotherapy, radiation, infections, severe stress, and mechanical trauma. The mucosal injury is often multifocal and tends to involve the body of the stomach. The injury can be mild such as superficial hemorrhage and edema, consist of sloughing of the superficial part of the mucosa--EROSION--or penetrate the muscularis mucosa--ULCER.

The pathogenesis of acute gastritis and acute (stress) ulcers is injury by the back diffusion of acid. The mucosal defense system is overwhelmed by the injurious forces and thus, does not protect adequately from acid injury.

The deficiency in mucosal defenses can include:

• disruption of the mucous layer
  
  
• decreased production of bicarbonate
  
  
• reduced mucosal blood flow
  
  
• decreased prostaglandin production (such as with NSAIDs)
  
  
• direct damage to the epithelium

Peptic Ulcers
Chronic, most often solitary lesions that occur most often in the first part of the duodenum followed by the antrum of the stomach. When in the stomach, the ulcers are located preferentially on the lesser curve of the stomach at the junction of the body and antrum (angularis). Peptic ulcers require exposure of the mucosa to acid and pepsin but these chemicals do not have to be elevated for an ulcer to occur. H. pylori infection is present in almost all patients with duodenal ulcers and a bout half with gastric ulcers. Chronic gastritis is present in the mucosa around these ulcers. Only about 10-20% of patients with H. pylori infection develop ulcers and there is a lot of research under way to try and elucidate which patients are at greater risk of significant gastritis and ulcers. Other coexisting agents that damage the mucosa play a role in some, for example drugs and smoking.

Complications
Bleeding occurs in 33% of patients and may be severe requiring emergent surgery. Perforation is rarer, but accounts for the majority of deaths. Obstruction is uncommon but occurs after healing of the ulcer results in a fibrous stricture.

Gastric Carcinoma
One of the leading causes of US cancer deaths (3%). Prognosis is largely related to depth of invasion of the tumor. A frequent location for carcinoma is the lesser curvature of the antropyloric region. This is the same site as peptic ulcers so there is a great need for tissue diagnosis. An ulcerative lesion on the greater curvature is more likely to be malignant.

There are two morphologic types:

1. Intestinal--type adenocarcinoma
   
   
   • Metaplasia-dysplasia-carcinoma sequence
     
     
     
   • Decreasing in frequency in the United States  
     
     
     
2. Diffuse--type adenocarcinoma linitis plastica
   
   
   • Arises from gastric mucous cells (not in setting of gastritis)
     
     
     
   • Frequency constant and now represents 50%
     
     
     
   • Younger age than intestinal type with equal sex ratio
     
     
     
   • Sheets of individual cells that often are signet cell in type

Whatever the type, these tumors have a propensity to involve a supraclavicular lymph node (Virchow's node) or to involve the ovaries bilaterally (Krukenberg tumor). Finding an enlarged node in this area is a significant clinical sign and should be investigated.

Digital Legends for Labs
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Lab 13 | Lab 14 | Lab 15 | Lab 15b | Lab 16 | Lab 16b | Lab 17 | Lab 18

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Updated September 5, 2007