[Biopsy methods and pathology of Barrett's esophagus]

We reviewed the definition of the esophagogastric junction and the biopsy sites and histologic findings of biopsy specimens from Barrett's esophagus. The borderline between the esophagus and stomach has been defined as the distal limit of the longitudinal vessels by the Japan Esophageal Society, because the longitudinal vessels are always located within the esophagus. As squamous islands in Barrett's mucosa are usually the orifices of esophageal glands proper, biopsy specimens from the squamous islands show esophageal glands proper or their ducts. The identification of esophageal glands proper is a definite histological indicator that a piece of biopsy tissue is of esophageal origin. Therefore, a diagnosis of Barrett's esophagus can be made purely on the basis of the histologic findings in these biopsy specimens of squamous islands. Since columnar mucosa is usually recognizable at endoscopy, a diagnosis of Barrett's esophagus can be made solely on the basis of endoscopic examination, without any need for histologic confirmation, if squamous islands are recognized in columnar-lined mucosa.