Drug-induced Injury, Infections, and Congenital and Miscellaneous Disorders

Aside from gastroesophageal reflux disease and eosinophilic esophagitis, various other inflammatory and congenital disorders can affect the esophagus. This chapter discusses this wide variety of esophageal abnormalities and highlights their characteristic pathologic features. The most common of these abnormalities are infectious and treatment/drug-induced disorders-both are very frequently encountered by the practicing surgical pathologist and can have pathognomonic histologic features, which can be supported by special studies (e.g., fungal and viral infections). Other conditions such as congenital/developmental disorders are less frequently encountered in practice but are also well described here. Some histologic patterns of injuries, such as lymphocytic esophagitis and esophagitis dissecans superficialis, are rather unique and can be associated with a number of clinical conditions; the pathology of these lesions is detailed here. Further, the esophagus can sometimes get involved in systemic inflammatory and autoimmune conditions, including those primarily affecting the gastrointestinal tract (Crohn’s disease) or the skin (e.g., lichen planus). This chapter also discusses mechanical and corrosive esophageal injuries, as well as esophageal achalasia, an esophageal motility disorder characterized by incomplete lower esophageal sphincter relaxation, which results in increased lower esophageal sphincter tone and lack of peristalsis of the esophagus. Finally, pathological features of other benign lesions such as hyperplastic polyps, squamous papilloma, glycogenic acanthosis, and other miscellaneous conditions are also discussed.