咽頭表在癌の特徴と鑑別診断―内視鏡の立場から

Magnifying Endoscopic Diagnosis of Middle and Hypopharyngeal Lesions: Particularly Focusing on Differential Diagnosis

要旨　ヨード染色が困難な中・下咽頭における表在癌の内視鏡診断は，NBI観察によるbrownish areaの拾い上げと，NBI拡大内視鏡による血管パターンの評価による．基本的には食道で適用しているIPCLパターン分類を，咽頭にもそのまま適応することができる．咽頭における鑑別診断の特徴は，リンパ装置が発達していること，乳頭腫が多いことなどである．その典型像の鑑別は容易である．しかし，時に乳頭腫と上皮内腫瘍の鑑別が困難な場合がある．

　Superficial cancer in the middle and hypopharynx can be detected by careful observation. It is impossible to spray iodine solution in the pharynx because it irritates the larynx, so NBI（narrow band imaging）becomes the key tool to identify flat lesions in the pharynx. After detecting a brownish area in the pharynx, NBI magnifying observation facilitates the evaluation of IPCL（intra-epithelial papillary capillary loop）pattern changes. An importanat differential diagnosis in the pharynx is squamous cell papilloma. Papillomatous lesions are easily diagnosed as squamous cell papilloma by typical endoscopic findings, but in flat lesions endoscopic diagnosis often becomes difficult.