[Pathological study of 936 cases of smooth muscle tumor in the alimentary tract]

936 cases of smooth muscle tumor were analysed, including 198 cases in esophagus, 354 in stomach, 243 in small intestine, and 141 in the large bowel. Pathological diagnosis revealed, that there were 468 cases of either leiomyoma or leiomyosarcoma, and the leiomyosarcoma cases had been further divided into three grades. The follow-up data of 191 leiomyomas showed that except 15 patients who died of irrelevant reasons, all the rest survived. Of 252 leiomyosarcoma patients, 138 are still alive and 114 died. The survival rate was 36.1% for 5 years and 30.1% for 10 years. Factors having an effect on the prognosis include sites, sizes, grades of the tumor and the number of mitotic figure in leiomyosarcoma. The authors suggest that mitotic figures (greater than or equal to 2/25HPF); cell anaplasia; density of tumor cell; tumor size (greater than 6cm); presence of necrosis and cystic change and infiltration of tumor cells into the neighbouring tissue may be considered as the criteria for the diagnosis of malignant smooth muscle tumors of the alimentary tract.