中・下咽頭表在癌の内視鏡診断―経鼻内視鏡の立場から

Transnasal Endoscopy for Diagnosing Superficial Oro-hypopharyngeal Cancer

要旨　食道癌治療前後の咽喉頭スクリーニング目的に経鼻内視鏡を導入し，経鼻内視鏡発見例8例を含む， 21例24病変を観察した．大きさ別では5mm以下3病変，5～10mm 2病変，10～20mm 8病変，20mm～ 11病変であった．5mmを超える21病変中20病変（95％）は，“領域性”とFICE＋近接観察での“dot状血管の密な増生”をもとに経鼻内視鏡でも存在診断が可能であったが，5mm以下の病変の拾い上げは困難であった．また内視鏡治療を行った17病変中13病変（76％）は，ヨードでの不染域と経鼻内視鏡による範囲診断がほぼ一致した．咽頭観察において， 患者負担が少なく，詳細な観察が可能な経鼻内視鏡検査は今後標準的な咽喉頭スクリーニング検査法となりうる．

　This report describes the clinical efficacy of transnasal endoscopy using white-light imaging or FICE（flexible spectral imaging color enhancement）for the diagnosis of superficial oro-hypopharyngeal cancers. 74 superficial oro-hypopharyngeal cancers were found in 56 patients associated with esophageal cancers between August, 1996 and August, 2009. Among them, 8 lesions were detected by transnasal endoscopy. 21 patients with a combined 24 lesions underwent a transnasal endoscopic study before the medical treatment. The diameters of the tumors were ; 3 lesions of 5mm or less, 2 lesions of 5～10mm, 8 lesions of 10～20mm, and 11 lesions of 20mm or more. 20 of 21 lesions over 5mm（96％）were detected by transnasal endoscopy. Most of them appeared as well demarcated brownish areas and scattered brown dots on FICE image. It was difficult to detect the lesions smaller than 5mm by transnasal endoscopy. An endoscopic resection was performed for 17 lesions. 8 lesions were histologically confirmed to be carcinoma in situ, and 9 lesions showed invasion into the subepithelial tissue. It was possible to predict the range of tumor in 13 lesions（76％）by comparison with the area unstained by iodine. Therefore, although the resolving power and manipulation performance are not optimal, FICE can detect lesions greater than 5mm in diameter. The observation of the oro-hypopharynx by transnasal endoscopy is easy and feasible because of its attenuation of gag reflex. Transnasal endoscopy may therefore become the standard examination modality for screening of the oro-hypopharynx in the future.