ESD後のsurveillanceで発見されたLSBE内の異時多発癌—Stepwise ESDの有用性

Metachronous Multiple Cancers Diagnosed within Long-segment Barrett's Esophagus during Surveillance after Endoscopic Submucosal Dissection:The Usefulness of Stepwise Endoscopic Submucosal Dissection

要旨●患者は40歳代，男性．食道隆起性病変の精査目的で紹介された．C3M6のLSBE後壁に0-IIa型病変を認めたが，その境界は不明瞭であった．NBI-MEにて0-IIa型病変の外側にも不整な表面構造が認められ，0-IIb＋“IIa”型と診断した．ESDにて一括切除し，最終病理診断は，0-IIb＋“IIa”，adenocarcinoma，tub1，pT1a-DMM，ly0，v0，pHM0，pVM0，45×43mmで胃型優位の混合型癌であった．ESD潰瘍は狭窄なく瘢痕化し，残Barrett食道はC0M3であった．以後，年に2回の内視鏡surveillanceを施行したところ，2年6か月後に，残Barrett粘膜に2個の異時多発癌を認め，両病変を合わせてESDを施行した．全割標本を作製したところ，術前未診断の第3病変も認められ，3病変ともにpT1a-SMMで治癒切除であった．2回目のESD潰瘍は扁平上皮で再生され，さらにC0M3のBarrett粘膜が遺残していた．再度，異時多発癌を来す危険性が高いと考えられたため，2回目のESDから6か月後に残Barrett粘膜に対するstepwise ESDを施行した．高度の線維化のためトリアムシノロン局注は不可能であり，プレドニゾロン40mgの経口投与を施行したが，狭窄を来しEBDを2回施行した．stepwise ESD潰瘍は扁平上皮で再生され，Barrett食道そのものが完全に扁平上皮化した．以後8年間，無再発生存中である．本邦の食道癌診療ガイドラインでは残Barrett食道に対しては経過観察が標準とされているが，LSBE内に発生したEACでは異時多発癌が多いため，残Barrett粘膜に対する治療の標準化が必要と考えられた．

　The patient was a 40-year-old man who had been referred to us for a detailed examination of an elevated lesion in the esophagus. A 0-IIa lesion was observed on the posterior wall of C3M6 LSBE（long-segment Barrett's esophagus）; however, its boundaries were unclear. NBIME（magnified endoscopy with narrow-band imaging）revealed irregular surface structures on the outside of the lesion, leading to a diagnosis of 0-IIb＋“IIa”disease. ESD（endoscopic submucosal dissection）was performed to excise the entire lesion, and the final pathological diagnosis was of 0-IIb＋“IIa”, adenocarcinoma, tub1, T1a-DMM, ly0, v0, HM0, VM0, 45×43mm, mixed with gastric type predominance. ESD ulceration turned into a scar without stenosis, and residual Barrett's esophagus was C0M3. Thereafter, endoscopic surveillance was performed twice a year. Two years and 6 months later, two metachronous cancers were found in the remaining Barrett's mucosa, and ESD was performed for both lesions. When whole-mount sections were prepared, a third lesion that had not been diagnosed prior to ESD was also found. All three lesions were T1a-SMM and curatively resected. The ulceration from the second ESD was regenerated with squamous epithelium, and vestigial remnants of C0M3 Barrett's mucosa were seen. As there was a high risk of metachronous multiple cancers relapse, stepwise ESD was performed 6 months after the second ESD for the remaining Barrett's mucosa. Because a local injection of triamcinolone was not feasible due to severe fibrosis, 40mg of oral prednisolone was administered ; however, stenosis was observed and ESD had to be performed twice. The stepwise ESD ulceration was regenerated with squamous epithelium, and Barrett's esophagus itself was completely epithelialized. The patient is alive with no relapses for 8 years since then.

　According to the Japanese guidelines for the management of esophageal cancer, endoscopic surveillance is the standard for residual Barrett's esophagus. However, as there is relatively high risk of metachronous multiple cancers in the residual Barrett's mucosa in LSBE, standardizing the treatment for residual Barrett's mucosa is considered necessary.