内視鏡的に切除した食道類基底細胞（扁平上皮）癌の2例

Basaloid (Squamous) Carcinoma of the Esophagus Treated with Endoscopic Resection, Report of Two Cases

要旨　〔症例1〕59歳，男性．内視鏡検査で門歯より32cmに立ち上がりなだらかな丈の低い隆起性病変（0-IIa）を認めた．隆起の表面は平滑で大部分が正常上皮に覆われていたが，頂部に浅い陥凹が認められた．X線検査では表面はやや顆粒状であった．生検では扁平上皮癌を疑う異型上皮が認められ，内視鏡的に切除した．腫瘍径は8×8mm，深達度sm₂（520μm）で，ly₀，v₀であった．なお，門歯より22cmにも半周性のm₂癌が認められた．〔症例2〕76歳の男性で，内視鏡的に切除された同時多発性食道早期癌の追跡中，中部食道に粘膜下腫瘍様隆起（0-Isep）が認められた．表面は正常上皮に覆われ平滑であったが，丈が高く緊満感を伴っていた．X線検査では立ち上がりはやや不整で，表面には淡いバリウム斑が認められた．生検では扁平上皮癌が疑われ，内視鏡的に切除した．腫瘍径は9×7mm，深達度sm₂（2,600μm）で，ly₀，v₀であった．いずれも放射線治療を追加し4年8か月，3年2か月間，無再発生存中である．

　〔Case 1〕A 59-year-old male. Endoscopic examination showed a slightly elevated lesion with smooth surface largely covered with normal mucosa and a small shallow depression (0-IIa) at 32 cm distal from the incisor. On X-ray examination, the surface of the tumor revealed a slightly granular appearance. Pathological findings of the biopsied specimen were suggestive of squamous cell carcinoma, but were not diagnosed as basaloid (squamous) carcinoma. The lesion was treated with endoscopic resection. The tumor measured 8×8 mm in size, and was diagnosed histologically as basaloid carcinoma, sm2 (520μm), ly0, v0, infβ. Another lesion (0-IIc, m2) was also found synchronously by endoscopic examination at 22 cm distal from the incisor.

　〔Case 2〕A 76-year-old male with a history of three lesions of synchronous early squamous cell carcinomas treated with endoscopic resection. The patient was followed up by endoscopic examination, and a small metachronous submucosal tumor-like protrusion was found 25 cm distal from the incisor (0-Isep). X-ray examination revealed a protrusion with a relatively distinct and slightly irregular margin and barium flecks on the surface of the tumor. Pathological features of the biopsied specimen were highly suggestive of squamous cell carcinoma. Before resection, the lesion was therefore suspected to be a mucosal cancer arising on a submucosal tumor such as a leiomyoma. The lesion was resected endoscopically, and the tumor measured 9×7 mm in size, and was diagnosed histologically as a basaloid (squamous) carcinoma, sm2 (2,600μm), ly0, v0, infα. Both patients refused additional surgical resection, and were treated with adjuvant irradiation therapy. Since receiving this type of therapy, the patients have survived for 56 months and 38 months respectively without recurrence.