頸部食道癌の内視鏡診断

Endoscopic Diagnosis of Cervical Esophageal Cancer

要旨●2007〜2016年に経験した頸部食道表在癌55例57病変（男性46例，女性9例）を対象に検討した．他院発見が8例8病変（14.0%），当院発見が47例49病変〔86.0%（食道癌EMR/ESD後36.8%，食道癌術後26.3%，同時性多発癌7.0%，他臓器癌10.5%，一般検査5.3%）〕であった．当院の内視鏡検査は，挿入時は白色光を主体に，抜去時はNBIで観察を行っている．挿入時の白色光観察で発見した13病変中6病変（46.2%）は，T1a-MM以深癌であった．抜去時のNBI観察で発見した21病変中17病変（81.0%）は15mm以下であり，T1b-SM癌が2病変含まれるも，大半はT1a-LPMまでの癌であった．食道入口部近傍の3病変を含め，6病変の発見にはアタッチメント装着が有用であった．57病変の腫瘍長径は，最小2mmから最大43mmであり，病変の約80%は20mm以内であった．病型は，0-I型が2病変（3.5%），0-IIa型および0-IIa型の混合型が10病変（17.5%），0-IIb型が7病変（12.3%），0-IIc型が38病変（66.7%）であった．深達度は，T1a-EP癌が32病変（56.1%），T1a-LPM癌が12病変（21.1%），T1a-MM癌が7病変（12.3%），T1b-SM1癌が2病変（3.5%），T1b-SM2癌が4病変（7.0%）であり，T1a-LPMまでの癌が約77%を占めていた．T1a-MM癌1病変とT1b-SM2癌2病変の3病変は脈管侵襲陽性，T1b-SM1癌1病変はINFcであった．頸部食道表在癌を効率よく発見するためには，食道癌の既往や，多発ヨード不染を有する症例を中心に，鎮静剤使用下で内視鏡検査を行い，NBIで観察する．頸部食道の内視鏡観察は食道入口部を越え，咽頭部まで行うが，病変との距離間が保てない場合はアタッチメントやキャップ，フードなどを装着して観察する．

　We investigated 55 patients（46 males and 9 females）with 57 lesions of superficial cancer of the cervical esophagus between 2007 and 2016. Lesions of eight patients（14.0%）were detected at other hospitals, and 49 lesions in 47 patients（86.0%）were detected at our hospital（after endoscopic treatment of esophageal cancer, 36.8% ; after surgery of esophageal cancer, 26.3% ; synchronous cancer, 7.0% ; cancers of multiple organs, 10.5% ; and general examination, 5.3%）. At our hospital, primary observation was conducted via endoscopic examination using white light during the insertion phase and NBI during the withdrawal phase. In this study, 6 of 13 lesions（46.2%）detected with white light during the insertion phase were T1a-MM or deeper cancer. Meanwhile, 17 of 21 lesions（81.0%）detected with NBI during the withdrawal phase were <15mm in size, and a majority of them invaded up to T1a-LPM. However, they included two lesions of T1b-SM cancer. Attachments were useful for detecting six lesions, including three lesions near the esophageal inlet.

　The long diameters of 57 lesions ranged from 2 to 43mm, and 80% of these lesions were within 20mm in size. The disease type included type 0-I in 2 lesions（3.5%）, type 0-IIa and mixed-type 0-IIa in 10 lesions（17.5%）, type 0-IIb in 7 lesions（12.3%）, and type 0-IIc in 38 lesions（66.7%）. The depth of invasion included T1a-EP cancer in 32 lesions（56.1%）, T1a-LPM cancer in 12 lesions（21.1%）, T1a-MM cancer in 7 lesions（12.3%）, T1b-SM1 cancer in 2 lesions（3.5%）, and T1b-SM2 cancer in 4 lesions（7.0%）. Thus 77% of lesions invaded up to T1a-LPM. Three lesions, including one lesion of T1a-MM cancer and two lesions of T1b-SM2, were positive for vascular invasion, and one lesion of T1b-SM1 cancer was INFc.

　The efficient detection of superficial cancer of the cervical esophagus can be achieved by observation with NBI endoscopic examination using sedatives, primarily in patients with a history of esophageal cancer and multiple iodine-unstained lesions. In endoscopic observation of the cervical esophagus, the endoscope reaches the pharyngeal region, going through the esophageal inlet. When a sense of distance to lesions cannot be gauged, observation should be performed with the endoscope equipped with attachments, caps, hoods, etc.