[Smooth muscle tumors of gastrointestinal tract: a study on correlation between pathology and prognosis and...

Seventy three cases of gastrointestinal smooth muscle tumors (GISMT) were collected and their correlation between pathology and prognosis and their histogenesis was studied, microscopically, the following parameters were evaluated: 1. cellularity; 2. grade of differentiation; 3. nuclear pleomorphism; 4. mitotic rate/10 HPF. All cases were followed up, but from only 47 information was elicited. To study the histogenesis, the technique of immunohistochemical staining to desmin, S-100 protein was used in all the cases and five were examined by EM. The results showed that the mitotic rate was the most important and reliable pathological parameter used to differentiate between benign and malignant tumors, and to evaluate the prognosis of a given tumor; in the cases which showed active mitosis, tumor size was important to evaluate the prognosis; the other histologic parameters of less, if any, significance in evaluation of prognosis. The authors supported the hypothesis that GISMT might mainly be derived from primary mesenchymal cells potentiated with smooth muscle cells differentiation. The hypothesis that GISMT are derived from nerve tissue waits for further evidence.