咽頭癌の内視鏡診断─経鼻内視鏡

Endoscopic Diagnosis of Early Pharyngeal Cancer Using Trans-nasal Endoscopy

要旨●経鼻内視鏡は，ここ数年で画質が格段に向上し，NBIやBLI，LCIといった画像強調内視鏡を備え，また中咽頭反転法やValsalva法などの活用により，これまで経口内視鏡の死角となっていた舌根や下咽頭後壁，輪状後部などの観察が容易となった．当科では1996年から咽頭表在癌の内視鏡治療を開始しているが，経口内視鏡で現在までに拾い上げた頭頸部表在癌は77例97病変に対し，2008年より経鼻内視鏡で拾い上げたのは164例227病変と倍以上に増加した．領域性のある発赤，正常血管網の消失，微細な小白苔の付着，ドット状またはイクラ状の異常血管の同定が拾い上げに有用で，深達度診断には十分に咽頭粘膜を伸展して，0-I型の隆起成分の有無を頼りにするとよい．

　The development of trans-nasal endoscopy with image-enhanced endoscopy（NBI, BLI, and LCI）now enables wider observation ; this method can be used to obtain adequate information for diagnosing early pharyngeal cancers without magnification. We initially started using endoscopic treatment for superficial pharyngeal cancer in 1996. Between 1996 and the present day, 77 cases in 97 lesions of superficial head and neck cancers were detected using trans-oral endoscopy. Between 2008 and 2016, 164 cases in 227 lesions were detected using trans-nasal endoscopy, which is more than twice the number of cases detected using other means. Mucosal redness ; loss of normal vascular pattern or white deposits ; and proliferation of vascular patterns, such as small dots or salmon roe, are important characteristics for the diagnosis of superficial pharyngeal cancer. Moreover, the use of image-enhanced endoscopy to identify brownish areas is useful for early diagnosis. With adequate extension of the pharyngeal mucosa using the Valsalva maneuver, the observation of protruded areas will be useful for diagnosing the depth of invasion.