Pathophysiology
Summary
Esophageal cancers and dysmotility disorders are key pathologies of the esophagus that have dysphagia as a common presenting symptom.
Esophageal adenocarcinoma originates in the distal 1/3 of the esophagus and often arises as a complication of GERD & Barrett’s esophagus, especially in smokers. Barrett's esophagus is a metaplasia of normal stratified squamous epithelium to intestinal columnar epithelium and exhibits gland-like features histologically.
Esophageal squamous cell carcinoma is the most common esophageal cancer worldwide and occurs primarily in the middle 1/3 of the esophagus. It is associated with irritants like N-nitroso compounds in some foods, hot beverages, betel nuts, alcohol, and smoking. Features include keratin pearls and intercellular bridging on histology and raised plaques with ulceration.
Both types of esophageal cancer typically present at first with dysphagia for solids, eventually progressing to dysphagia for liquids. Both types also commonly present with weight loss and odynophagia. A rare condition known as Plummer-Vinson syndrome can increase the risk for squamous cell carcinoma. It results from chronic iron deficiency and leads to esophageal webs that allow liquids to pass, causing dysphagia for solids only.
Esophageal motility disorders can present in various forms such as achalasia, diffuse esophageal spasm, and in systemic conditions like CREST syndrome. Achalasia presents as a bird-beak sign on barium swallow and results from impaired relaxation of the LES due to the loss of the myenteric plexus, leading to decreased production of neurotransmitters like NO and vasoactive intestinal peptide (VIP). The primary etiology is idiopathic, though it can occur in conditions like Chagas disease. Diffuse esophageal spasm causes diffuse uncoordinated contractions that can be mistook for angina, and is visualized as a strong>corkscrew esophagus on barium swallow. CREST syndrome, a form of systemic sclerosis, leads to fibrous replacement of the muscularis in the LES, leading to dysphagia and GERD.
Lesson Outline
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FAQs
Esophageal dysmotility disorders like achalasia and diffuse esophageal spasm can lead to chronic irritation of the esophageal lining, thereby increasing the risk of developing esophageal cancer. Additionally, conditions such as Plummer-Vinson syndrome are directly associated with a heightened risk of esophageal squamous cell carcinoma.
Esophageal adenocarcinoma and squamous cell carcinoma differ in several aspects including risk factors, prevalence, and anatomical location. Adenocarcinoma is the most common type of esophageal cancer in the United States and is often linked to Barrett's esophagus and smoking. It primarily affects the distal third of the esophagus. On the other hand, squamous cell carcinoma is more prevalent worldwide and is associated with risk factors such as alcohol consumption, hot beverages, and tobacco use. This type usually occurs in the middle third of the esophagus.
Esophageal adenocarcinoma is commonly associated with Barrett's esophagus, a condition that often develops due to chronic gastroesophageal reflux disease (GERD). GERD predominantly affects the distal third of the esophagus, including the gastroesophageal junction. This localized impact explains why adenocarcinoma is most frequently found in the distal third of the esophagus.
Both types of esophageal cancer, adenocarcinoma and squamous cell carcinoma, initially present with dysphagia for solids, which eventually progresses to include liquids. Other common symptoms include weight loss and odynophagia, or painful swallowing. In the case of squamous cell carcinoma, patients may also exhibit raised plaques with ulceration on endoscopic examination.
Systemic conditions can have a significant impact on esophageal function. Plummer-Vinson syndrome, caused by chronic iron deficiency, leads to the formation of esophageal webs in the upper third of the esophagus, causing dysphagia for solids. CREST syndrome, a variant of systemic sclerosis, results in fibrous replacement of the muscularis in the lower esophagus, leading to dysphagia for both solids and liquids and potentially causing gastroesophageal reflux disease (GERD).
