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Alimentary Tract


Five common radiological abnormalities are found in the esophagus: stricture or tumor, diverticulum, neuromuscular dysfunction (achalasia), varices, and hiatus hernia.

Tumors or Strictures. Most tumors or strictures are due to malignancy, although in many parts of the tropics corrosive strictures will be seen because of the use of caustic soda in home soap making. The incidence of cancer, whether seen as a stricture or tumor, varies considerably in different parts of the tropical world (see Chapter 43 on Geographic Variations of Malignant Neoplastic Diseases).

Diverticula. The large diverticulum in the cervical esophagus (Zenker's) is found with the same frequency in any part of the world, but the small diverticulum at the level of the aortic arch or tracheal bifurcation is very rare in many parts of the tropics, and particularly throughout Africa (Fig. 44.4). Thus, any local esophageal abnormality that radiologically suggests a diverticulum should be very carefully examined to exclude malignancy, because this is statistically far more likely. The "diverticulum" may be the beginning of an esophagobronchial fistula through the tumor.



Fig. 44.4A-D. Diverticula of the esophagus are uncommon, even rare, in many parts of the tropics; when present, they usually occur at about the level of the tracheal bifurcation and they do not appear to have any association with mediastinal lymphadenopathy. (A) Two projections of a barium swallow of a large "pouch" in the middle third of the esophagus. (B) A similar posterior diverticulum in a different patient. Both patients (A and B) came from southern Africa. (C,D) Benign strictures are very difficult to differentiate from carcinoma of the esophagus. (C) A short stricture in the lower third of the esophagus and (D) a long irregular stricture starting just below the thoracic inlet. Both are the result of West Africans swallowing lye (caustic). CT or MRI may help differentiation by demonstrating a tumor, but inflammation, edema, and a fistula may produce a similar effect.

Neuromuscular Dysfunction: Achalasia. Achalasia, or the different neuromuscular dysfunction known as "corkscrew esophagus," may be recognized anywhere in the world. In some parts of Africa, achalasia is associated with bilateral parotid gland enlargement; the etiology is unknown, but it may be an effect of malnutrition. In India, the "corkscrew esophagus" is often associated with malnutrition in the elderly. In Brazil and several other South American countries, a dilated esophagus usually indicates chronic Chagas' disease. In many countries, a dilated esophagus will be due to a carcinoma in the region of the cardia; tuberculosis can produce the same effect.

Esophageal Varices. Esophageal varices are common in many tropical countries because of cirrhosis, the result of either protein malnutrition or schistosomiasis in the majority of patients.

Hiatus Hernia. As elsewhere, hiatus hernia is a frequent occurrence in the tropics, but is very seldom the cause of symptoms. There is some geographic variation (e.g., it is reported as rare in the Sudan) but this must also depend on the availability and enthusiasm of radiologists.

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Copyright: Palmer and Reeder