食道胃接合部に発生し印環細胞成分を伴った腺内分泌細胞癌の1例

Mixed Adeno-neuroendocrine Carcinoma with Signet-ring Cells in the Esophago-Gastric Junction, Report of a Case

要旨●患者は68歳，男性．自覚症状なし．上部消化管内視鏡検査にて食道胃接合部に長径20mmの隆起性病変を認め，頂部に不整形陥凹を伴っていた．病変の立ち上がりは粘膜下腫瘍様で非腫瘍性粘膜に覆われて陥凹面は発赤調粗糙粘膜であった．NBI併用拡大観察で陥凹部にループ形成の乏しい異常血管がみられ，一部でType R様の網状血管を認めた．生検で中〜低分化腺癌が検出され，下部食道・噴門側胃切除術を施行した．切除病理標本で腫瘍は粘膜下層を主体に増殖した腺内分泌細胞癌で，大部分は内分泌細胞癌であったが，管状腺癌の部分や印環細胞を呈する部分が併存し，陥凹部で表層に露出していた．術後化学療法を施行し9か月無再発生存中である．

　A 68-year-old man was referred to Kitakyushu municipal medical center for the evaluation and management of a protruded lesion in the lower esophagus. Conventional endoscopy showed a 20mm elevated lesion with a central irregular depression located in the esophagogastric area. The leading edge of the lesion was a submucosal tumor-like elevation covered with a non-neoplastic epithelium, and the surface of the depression was red and coarse. Narrow-band imaging magnified endoscopy revealed non-loop irregular vessels on the surface of the depression, and reticular vessels-like type R（as per the Japan Esophageal Society classification）were partially seen. The biopsy specimen was diagnosed as a moderately to poorly differentiated adenocarcinoma, so we performed resection of the lower esophagus and fundusectomy. Pathological examination of the specimens revealed that the tumor consisted of a mixed adenoneuroendocrine carcinoma, mainly neuroendocrine carcinoma, arising from the submucosal layer, with tubular adenocarcinoma and signet-ring cells present in the depression, which were exposed to the surface. He was treated with adjuvant chemotherapy and remains alive without evidence of recurrence 9 months after surgery.