RESUMO
The study of 36 cases of gastrointestinal stromal tumors (GIST) (n = 26 of the stomach and n = 10 of the duodenum, small bowel, and rectum) indicated that among the clinical symptoms, there were prevalent abdominal pains and gastrointestinal bleeding. Local invasion and metastases were detected in 11 patients. According to the risk of aggressiveness, 1 tumor presented a very low risk; 5, a low risk; 14, a moderate risk; and 16 a high risk. All GISTs with mucosal infiltration were in high and moderate risk groups. The expression of p27 did not depend on that of other markers, the sizes of a tumor, its histological type, and affinity to this or that risk group. There was a statistically significant difference in the expression of Ki-67 in the groups of low (1.7%) and high (10.3%) risks.