胃の平滑筋芽細胞腫の2例

Bizarre Leiomyoblastoma of the Stomach: Report of two cases

　胃の平滑筋芽細胞腫は，1960年Martin¹⁾により．平滑筋腫瘍の中に特殊な細胞形態をとる一群が認められ，それらはmyoid tumorとして報告されたが，1962年にStout²⁾によりその呼称が与えられた稀な疾患で，平滑筋肉腫とは臨床的にも異なった経過をとる．特に予後に関してはほとんどが良好であり，ときに転移再発を起こすこともあるpotentially malignantな腫瘍である．最近われわれは2例の本症を経験したので若干の文献学的考察を加えて報告する．

症　例

〔症例1〕

　患　者：木○秀○　54歳　男　公務員

　主　訴：上腹部不快感

　現病歴：上記主訴以外に特に自覚症状はなかったが，職場の胃集団検診にて幽門部の陰影欠損を指摘され当院を受診した．

　Bizarre leiomyoblastoma named by Stout in 1962 is a rare submucosal tumor of the stomach. It is noted that the disease is characteristic by its clinical course. Most of the tumors are benign but some are potentially malignant, which would manifest metastasis or recurrence.

　Recently, we had two patients with bizarre leiomyoblastoma. Both of them have been healthy with no signs of recurrence for more than one year and five years, respectively, after subtotal gastrectomy.

　Macroscopically, extraluminally growing tumor was disclosed in one case in contrast to the other, in which the tumor developed intraluminally. At first, they were diagnosed erroneously as adenocarcinoma and leiomyoma respectively by histopathological examination but reexamination confirmed the correct diagnosis of bizarre leiomyoblastoma of the stomach.

　We should perform careful macroscopic and microscopic examinations of the resected stomach for findings of such a rare disease.