胸腔鏡下に摘出した全周性大型食道平滑筋腫の1例

A case of thoracoscopic enucleation of large leiomyoma involving the entire esophageal surface

◆要旨：患者は19歳，男性．主訴はなし．健康診断での胸部X線検査異常の精査のため，近医で上部消化管内視鏡検査が施行され，胸部下部食道に巨大粘膜下腫瘍を認め，当院紹介となった．画像検査で下部食道壁外に突出する最大80mm径の腫瘍を認めた．腫瘍は下部食道を全周性に取り囲む形態で存在していた．平滑筋腫を強く疑ったが，悪性の可能性も否定できないため，手術による切除の方針とした．手術は左下半側臥位の胸腔鏡下で行った．腫瘍と周囲臓器との境界は概ね疎な結合織であり，剝離は比較的容易であった．食道と腫瘍の剝離を鋭的に進め，食道を取り囲んだ腫瘍は，結果的に馬蹄状に摘出可能で，最後に筋層との由来となる腫瘍茎部を同定し食道外膜・固有筋層を一部切除する形で摘出した．食道壁欠損部は縫合閉鎖した．病理組織学的所見より食道平滑筋腫と診断した．現在，術後1年経過し無再発，無症状である．胸腔鏡下アプローチは，全周性大型食道平滑筋腫に対しても有用な術式と考えられたため，文献的考察を加え報告する．

　We report a case of a 19-year-old man who underwent thoracoscopic enucleation for resection of a large leiomyoma involving the entire esophageal surface. He denied any complaints; however, chest radiography revealed an abnormal shadow, and computed tomography and endoscopic ultrasonography revealed a large （8 cm） submucosal tumor in the lower thoracic esophagus. The tumor involved the entire circumference of the esophagus. We suspected leiomyoma, although malignancy could not be excluded. Therefore, we performed surgical resection. The operation was performed thoracoscopically with the patient placed in the left half prone position. The tumor was well demarcated from the surrounding organs by loose connective tissue, and resection was relatively easy. The tumor stalk was identifiable, and the esophageal adventitia and the intrinsic muscle layer were partially excised. Based on histopathological examination, the tumor was diagnosed as an esophageal leiomyoma. We recommend thoracoscopy as a useful technique for the resection of large esophageal leiomyomas.