食道平滑筋腫上に併存した早期食道癌の1例

Early Esophageal Cancer Coexisting with Esophageal Leiomyoma, Report of a Case

要旨　患者は57歳，女性．健診にて食道の異常陰影を指摘された．食道X線検査で胸部上部食道前壁に長径3cmの表面平滑な隆起性病変を認め，食道内視鏡検査では切歯より22cm部を中心に拇指頭大の腫瘤を認め，ヨード染色で一部不染域を認めた．同部の生検組織診断は食道扁平上皮癌であった．食道平滑筋腫上に併存した早期食道癌と診断し，胸部食道全摘術，胸骨後食道胃管吻合術を施行．切除標本では，連続する2個の平滑筋腫を認め，その表面に0-Ⅱb型，深達度epの早期食道癌が認められた．

　A rare case of superficial esophageal cancer coexisting with esophageal leiomyoma was reported. A 51 year-old woman was referred to our hospital without symptoms. Esophagography showed a protruding lesion (3.O×3.O cm in size) with a smooth surface at upper intrathoracic esophagus. Endoscopic examination revealed a thumb-sized tumor, and dye-spray technique showed an unstained area. Biopsy specimens of the lesion contained squamous cell carcinoma. Esophagectomy was performed. The resected specimen revealed superficial carcinoma over a submucosal tumor. Microscopic findings showed well differentiated squamous cell carcinoma confined to the epithelium and a sub-epithelial leiomyoma composed of interlaced bundles of spindle-shaped smooth muscle cells. The causative relation between the esophageal leiomyoma and the squamous cell cancer is unclear but in this case, constant mechanical stimulation may have caused malignant deterioration of the epithelium overlying the leiomyoma.