胃肉腫―内視鏡診断を中心に

Sarcoma of the Stomach, with Special Reference to its Endoscopic Diagnosis

はじめに

胃肉腫は，従来比較的まれな疾患とされ，その臨床診断は困難で，殆どが癌と誤診され，手術または剖検標本の組織学的検討によって，初めて正診が下されていた．しかし，近年X線，内視鏡，特に細胞診と生検の進歩普及により，漸次術前に正診が得られるようになって来た．

　筆者らは，1965年1月より1969年8月に至る約4年8カ月間に当科において内視鏡検査を実施し，手術あるいは剖検，一部は生検により，組織学的に胃肉腫と診断された16症例を経験した．

本稿においては，これら症例の主として内視鏡所見，一部内視鏡を用いた細胞診ならびに生検成績について検討し，併せて文献的考察を試みた．

　A total of 16 cases of stomach sarcoma with 8 leiomyosarcomas and 8 malignant lymphomas are reported with special reference to endoscopic findings, and cytological and biopsy studies of these cases are also presented.

　Leiomyosarcoma showed crater formation, and 75% of the cases were located on the cardiac area. Four cases of malignant lymphoma with ulcerative type were located on the cardiac or body area. The rest with infiltrative type were distributed widely on all the areas of the stomach. In the first endoscopic examinati on correct diagnosis was made in 25% of the cases, and more than a half of them were mistaken for cancer. However 68.8% were diagnosed finally as sarcoma from characteristic findings of the ulcer, multiple formation of irregular ulcers and infiltration.

　As for endoscopic findings of leiomyosarcoma, the margin of ulcer is sharply defined and embanked with glossy mucosa. The ulcer is relatively large being surrounded with undermined elevated wall. The bottom of the ulcer is covered with cream-like coat and is rugged. The mucosa appears to be generally soft. On the other hand, malignant lymphoma with ulcerative type shows almost the same findings as the former but, club-like swelling of the mucosal folds around crater and multiple formation of irregular ulcers are rather characteristic findings to differentiate malignant lymphoma from leiomyosarcoma.

　Malignant lymphoma with diffuse infiltrative type shows giant mucosal folds, nodule formation of various size, ulcers, erosions and hemorrhage which are relatively localized, and the mucosa is glossy with soft appearance.

　Cytology was positive in 9 of 10 cases and biopsy was also positive in 8 of the 10.

　Once endoscopic characteristics of stomach sarcoma are obtained, differential diagnosis from cancer or others is possible.

　Discrimination between leiomyosarcoma and malignant lymphoma is also relatively possible.

　Since diagnosis by macroscopic appearance is limited, cytology and biopsy must be performed together, and electron microscopic studies are also useful.