- The adult esophagus is a 25-cm tube. The lower esophageal sphincter is not a true anatomical sphincter but rather a functional one. Q
- The esophagus has a mucosa, submucosa, muscularis propria, and adventitia. The lymphatics of the upper third of the esophagus drain to cervical lymph nodes, those of the middle third to the mediastinal nodes, and those of the lower third to the celiac and gastric lymph nodes. These anatomic features are significant in the spread of esophageal cancer. Q
- Congenital Disorders
- Tracheoesophageal Fistula Leads To Aspiration Pneumonia
- Tracheoesophageal fistula is the most common esophageal anomaly. It is frequently combined with some form of esophageal atresia. In some cases, it is associated with a complex of anomalies identified by the acronym Vater syndrome (vertebral defects, anal atresia, tracheoesophageal fistula, and renal dysplasia). Q
- Maternal hydramnios has been recorded in some cases of esophageal atresia and, less commonly, in cases of tracheoesophageal fistula. Esophageal atresia and fistulas are often associated with congenital heart disease.
- Tracheoesophageal Fistula Leads To Aspiration Pneumonia
- In 90% of tracheoesophageal fistulas, the upper portion of the esophagus ends in a blind pouch and the superior end of the lower segment communicates with the trachea.
- In this type of atresia, the upper blind sac soon fills with mucus, which the infant then aspirates. Surgical correction is feasible albeit difficult.
- Plummer-Vinson (Paterson-Kelly) Syndrome:
- This disorder is characterized by (1) a cervical esophageal web, (2) mucosal lesions of the mouth and pharynx, and (3) iron-deficiency anemia. Dysphagia, often associated with aspiration of swallowed food, is the most common clinical manifestation.
- Ninety percent of cases occur in women. Carcinoma of the oropharynx and upper esophagus is a recognized complication of the Plummer-Vinson syndrome. Q
- Zenker Diverticulum:
- Zenker diverticulum (pulsion diverticulum) appears high in the esophagus and affects men more than women.
- Cause is disordered function of cricopharyngeal musculature.
- Seen in individuals older than 60, suggesting that this diverticulum is acquired.
- Zenker diverticula can enlarge conspicuously and accumulate a large amount of food. The typical symptom is regurgitation of food eaten some time previously (occasionally days), in the absence of dysphagia. Recurrent aspiration pneumonia may be a serious complication.
- The principal barrier to reflux of gastric contents into the esophagus is the lower esophageal sphincter. Transient reflux is a normal event, particularly after a meal. When these episodes become more frequent and are prolonged, esophagitis results.
- Agents that decrease the pressure of the lower esophageal sphincter (e.g., alcohol, chocolate, fatty foods, cigarette smoking) are also associated with reflux. Q Certain central nervous system depressants (e.g., morphine, diazepam), pregnancy, estrogen therapy, and the presence of a nasogastric tube may lead to reflux esophagitis.
Barrett Esophagus Is Replacement of Esophageal Squamous Epithelium by Columnar Epithelium
- Barrett esophagus is a result of chronic gastroesophageal reflux. Q This disorder occurs in the lower third of the esophagus.
- There is a slight male predominance and a more than twofold increased risk for Barrett esophagus among smokers. Patients with Barrett esophagus are placed in a regular surveillance program to detect early microscopic evidence of dysplastic mucosa. Q
- Microscopically, it consists of an admixture of intestine-like epithelium characterized by well-formed goblet cells interspersed with gastric foveolar cells.
- Barrett esophagus may transform into adenocarcinoma, the risk correlating with the length of the involved esophagus and the degree of dysplasia. Q
- Cigarette smoking increases risk of esophageal cancer 5- to 10-fold. The number of cigarettes smoked correlates with the presence of esophageal dysplasia. Q
- Excessive consumption of alcohol is a major risk factor.
- Increased levels of nitrosamines and other potentially carcinogenic compounds have been found in the diets of persons living in high-incidence areas. Q
- Diets low in fresh fruits, vegetables, animal protein, and trace metals are described in areas with endemic esophageal cancer, as are deficiencies of various vitamins and minerals.
- Plummer-Vinson syndrome, celiac sprue, and achalasia are associated with an increased incidence of esophageal cancer. Q
- Chronic esophagitis has been related to esophageal cancer in areas in which this tumor is endemic.
- About half of cases of esophageal cancer involve the lower third of the esophagus; the middle and upper thirds account for the remainder.
- Grossly, the tumors are of three types: (1) polypoid, which projects into the lumen, (2) ulcerating, which is usually smaller than polypoid and (3) infiltrating, in which the principal plane of growth is in the wall. Q
- The bulky polypoid tumors tend to obstruct early, whereas ulcerated ones are more likely to bleed. Infiltrating tumors gradually narrow the lumen by circumferential compression.
- Local extension of tumor into mediastinal structures is commonly a major problem.
- Microscopically, neoplastic squamous cells range from well differentiated, with epithelial pearls to poorly differentiated tumors that lack evidence of squamous differentiation.
- The rich lymphatic drainage of the esophagus provides a route for most metastases.
- Accordingly, tumors of the upper third metastasize to cervical, internal jugular, and supraclavicular nodes. Cancer of the middle third metastasizes to the paratracheal and hilar lymph nodes and to nodes in the aortic, cardiac, and paraesophageal regions. Q
- As the lower third of the esophagus is fed by the left gastric artery, lower esophageal tumors spread via accompanying lymphatics to retroperitoneal, celiac, and left gastric nodes.
- Metastases to liver and lung are common, but almost any organ may be involved. Q
- The most common presenting complaint is dysphagia, but by this time most tumors are unresectable.
- Patients with esophageal cancer are almost invariably cachectic, owing to anorexia, difficulty in swallowing, and the remote effects of a malignant tumor. Odynophagia occurs in half of patients and persistent pain suggests mediastinal extension of the tumor or involvement of spinal nerves.
- Compression of the recurrent laryngeal nerve produces hoarseness and tracheoesophageal fistula is manifested clinically by a chronic cough.
- Surgery and radiation therapy are useful for palliation, but the prognosis remains dismal.
- Many patients are inoperable and of those who undergo surgery, only 20% survive for 5 years.
4. Adenocarcinoma Of The Esophagus:
- As its incidence has recently increased, adenocarcinoma of the esophagus is now more common (60%) in the United States than squamous carcinoma. Virtually all adenocarcinomas arise in the background of Barrett esophagus, although a rare case originates in submucosal mucous glands. Q
Risk factor for adenocarcinoma
- Barrettâ€™s esophagus (Most important)
- Tobacco exposure
- Genetic alterations include over expression of p53, amplification of c-ERB-B2 and nuclear translocation of b catenin (biomarkers of disease progression).