著明な囊胞形成を伴った巨大胃平滑筋肉腫の1例

Huge Leiomyosarcoma of the Stomach Mimicking Cystic Tumor of the Pancreas, Report of a Case

要旨　患者は53歳，女性．1992年4月ごろから胃部不快感が出現．同年6月，近医での胃X線・内視鏡検査で胃体上部後壁に径約7cmの粘膜下腫瘍像と肛門側の圧排所見を認めた．CT上は膵尾部に接して約20cmの囊胞形成を伴った腫瘤が認められ，膵囊胞性疾患が疑われた．しかし，超音波内視鏡所見上，胃壁筋層と連続した径8cmの不整な充実性腫瘤部が描出され，血管造影検査でも左胃大網動脈から分枝した新生血管密生像を認めた．手術の結果，病理組織学的にも胃原発の平滑筋肉腫と診断された．リンパ節転移はなく，腫瘍は胃体部後壁から管外性に巨大発育しており，内部の著明な囊胞形成は凝血塊の貯溜によるものであった．

　A 53-year-old woman, who had a history of a traffic accident one month previously was referred to our hospital for an abdominal tumor. Abdominal computed tomography revealed a huge cystic mass (20×14×8cm), mimicking a cystic tumor of the pancreas. However, endoscopic ultrasonography demonstrated a heterogeneous solid component in the mass, originating from the proper muscle layer of the stomach. This feature was strongly suggestive of gastric leiomyosarcoma, and angiography also supported this diagnosis. Surgical operation was then carried out. Histological study of the resected specimen revealed leiomyosarcoma of the stomach with cystic formation of a huge hematoma.