Esophagus columnar epithelium

The esophagus is a musculomembranous conduit that extends from the pharynx to the stomach and is approximately 23-25 cm in length in an adult. It is lined by stratified squamous columnar epithelium and surrounded by a muscular layer composed of longitudinally arranged smooth muscle bundles. The submucosa contains many nerve fibers. It also contains submucosal glands, which are mainly present in the lower and upper portions of the esophagus and... 

By the 1970s, it was firmly established that the columnar-lined esophagus was often associated with severe GERD. There was controversy as to whether normal esophagus could be lined by columnar epithelium. 

This became a source of considerable concern with the widespread recognition of the relationship between adenocarcinoma and Barrett s esophagus. In the latter instances, the columnar epithelium surrounding the tumor invariably contained specialized intestinal metaplasia that often exhibited dysplasia. The recognition that specialized intestinal metaplasia was the epithelial type that predisposed to dysplasia and cancer development generated a major interest in the biology of this lesion and its early identification. 

The mouth and esophagus are composed of two layers, the mucosa and submucosa (Figure 3.5). The mucosa is lined on its outer surface by a stratified squamous epithelium with layers of polyhedral cells of the intermediate layers and low columnar cells of the basal layer. Below the cellular layer is the lamina propria containing loose connective tissue with blood vessels and small aggregates of lymphocytes. Smooth muscle within the mucosa (muscularis mucosal layer) is seen as small bundles. The submucosa... 

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