咽喉頭・食道の組織と腫瘍性疾患の病理

The pharynx, larynx, and esophagus: normal histology and the pathology of neoplastic lesions

要旨

　咽頭・食道の内視鏡診断に必要な，組織学的・病理学的な知識を整理する。口腔から食道は基本的には非角化重層扁平上皮に被覆されるため，ここに発生する癌の多くは扁平上皮癌である。上咽頭のリンパ球浸潤を伴う低分化な扁平上皮癌の発生にはEB virusが，中咽頭癌の一部の発生にはHPVが関与する。下咽頭と食道とは正常・腫瘍とも形態的に類似しているが，食道には存在する粘膜筋板を下咽頭では欠いているため，上皮下浸潤を伴う癌の壁深達度の評価方法が異なる。食道扁平上皮癌，Barrett食道腺癌の組織診断，深達度分類および食道上皮内腫瘍の病理診断の問題点についても述べた。

　This article describes the essential histological and pathological aspects required for endoscopic diagnosis of the pharyngolarynx and esophagus. The oral cavity to the esophagus is basically covered with non-keratinized stratified squamous epithelium, so most cancers occurring here are squamous cell carcinomas. EB virus is involved in the development of poorly differentiated squamous cell carcinoma with lymphocytic infiltration in the nasopharynx, and HPV is involved in the development of some oropharyngeal cancers. Normal and tumorous histology of the hypopharynx is similar to the esophagus, but the muscularis mucosae present in the esophagus are absent in the pharynx, so the methods for describing the invasion depth of cancer are different. We also describe the histological diagnosis and invasion depth classification of esophageal squamous cell carcinoma and Barrett's esophageal adenocarcinoma, and discuss problems with the pathological diagnosis of squamous intraepithelial neoplasia of the esophagus.