食道epidermizationの2例

Epidermization of the Esophagus, Report of Two Cases

要旨　食道におけるepidermizationの臨床像について，内視鏡像および病理組織像を中心に概説した．食道epidermizationは，組織学的に扁平上皮の表面に厚い角化層を有するのが特徴であり，この所見が皮膚の表皮に類似していることから，この名称で呼ばれている．epidermizationの内視鏡的特徴は，"鱗状"あるいは"毛羽立ちを有する"白色の付着物と表現され，同病変はルゴールには不染となる．肉眼的には，食道乳頭腫，錯角化，グリコーゲンアカントーシス，限局性食道炎，食道カンジダなどの良性病変に加えて，表在癌との鑑別が必要な病変である．われわれが検索した限りでは，epidermizationの報告は現在までほとんどないため，その真の成因や発生頻度は現段階では不明である．

　We described the clinical features of epidermization, focusing on endoscopic and histopathological findings. Since the pathological feature of this lesion is a keratinized layer at the surface of the epithelium resembling the epidermis, this lesion has been known as"epidermization". Endoscopically, epidermization seems to be adherent to the esophageal mucosa and to resemble plaques. It has a translucent white color, scaly or shaggy surface without erosion or ulceration, and retains an unstained appearance after staining with Lugol's iodine solution. Differential diagnosis needs to be made based on lesions with similar appearance, such as papilloma, hyperkeratosis, glycogenic acanthosis, localized esophagitis, esophageal candidiasis, and superficial esophageal cancer. To our knowledge, since there are few previous reports of epidermoid metaplasia, both the etiology and the frequency of epidermization are unknown at this time.