胃平滑筋腫瘍の臨床から見た良・悪性の鑑別診断―経過観察例を中心に

A Differential Diagnosis of Gastric Myogenic Tumors from the Clinical Course: From a Study of Course-observed Cases

要旨　Boring生検や外科手術により病理組織診断を得た胃平滑筋腫瘍127例（平滑筋腫91例，平滑筋肉腫29例，平滑筋芽腫7例）を対象として臨床像，発育形式・発育経過の検討を行った．腫瘍径の増大を経時的に計測できた52例に対しては，遡及的に発育速度（DT）を計算し，DTによる良・悪性の鑑別診断の可能性を検討した．平滑筋腫36例のDTは平均約3年だが，症例差が大きかった．悪性例のDTは平滑筋肉腫10例で平均7.7か月，平滑筋芽腫6例で平均9.0か月で，良性例と有意差があり，DTは良・悪性の鑑別に有用であると考えられる．組織診断の得られていない場合，平滑筋腫瘍に対する安易な経過観察は慎むべきであり，初回腫瘍径によっても経過観察期間を考慮すべきである．

　We studied clinical features, clinical course, and growth patterns of 127 series of gastric myogenic tumors (91 cases of leiomyoma, 29 cases of leiomyosarcoma, seven cases of leiomyoblastoma), whose histopathological diagnoses had been obtained from specimens by boring biopsies or surgical operations. We could measure increase in diameters of tumors of 52 cases serially, and calculated retrospectively the doubling time (DT) of them. Also, we made investigation into the ability of the differential diagnosis of malignancy from benignancy by DT. The mean DT of 36 cases of leiomyoma was about three years, but, there was a wide variety of DT in individual cases. As for the mean DT of malignant series, it was 7.7 months in 10 cases of leiomysarcoma, and 9.0 months in six cases of leiomyoblastoma. The DTs were significantly less than the average DT in the benign series. Thus, we concluded that calculating DT was a very useful way to differentially diagnose malignancy from benignancy. We must never observe cases of myogenic tumors lightly, if we have not yet obtained their histopathological diagnoses. And, we have to take account of diameters of the tumors at the first endoscopic examination, in order to decide a treatment plan. In paticular, it is necessary to decide an adequate period of observation.