Malignant gastrointestinale stromal tumor of the small intestine (15x13x11cm) and upcoming necroses. Infiltrations of the small intestine reaching to the Lamina epithelilalis mucosae and partially to the torn surface of the preparation. The omentum majus and the mesentery are extensively infiltrated. About 30% of events of illness are located in the small intestine, only the stomach is affected more often by this kind of space-consuming lesion. The used therapy consisted in a generous resection of the tumor. The dispensation of Imatinib is indicated for relapse prevention.