The Research Of Clinical Pathology Of Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors(GISTs) are common mesenchymal tumors of the gastrointestinal tract that are always diagnosed as leiomyosarcoma or (maglignant) peripheral nerve sheath tumor of gastrointestinal tract in a long-term. In the 1960's, the morphology varieties of leimyoma of gastrointestinal tract had led to pathologists' concern. In 1985, it was confirmed that epithelioid leiomyomas or invisible differentiation of shuttle cell tumors were indirection differentiation of GISTs. Because there still exsits many different views in the origin of this tumor, the determination of biology action and immunophenotype, domestic and foreign scholars paid great attention to it. After this, many scholars did not obtain valuable process in researching GISTs, until recent years they finally found this tumor existed c-kit(CD117) gene's mutation and the expression of protein, c-kit's (CD 117) positive rate approaches 100%, which is a remarkable immunohistochemical marker of GISTs. So many researchers suggested GISTs may originate from Cajal cells in the wall of gastrointestinal tract or mesenchymal stem cells. Cajal cell is the unique cell expressing CD117 and CD34 in gastrointestinal tract.GISTs have no obvious clinical symptoms, so it is difficult to diagnose. The histomorphology of GISTs is various. Some characters make it easier be diagnosed as other tumors. The basic morphology of GISTs consists of shuttle and epitheloid cells. Definite diagnosis of GISTs depends on pathomorphism, immunohistochemical and electron microscope. In terms of the suggestion which Sircar and Kindblom had put forward, the term GISTs should include the so called epitheloid smooth muscle tumors, traditional leiomyosarcomas, some spindle cell tumors with possible neural differentiation and tumors that show autonomic differentiation (plexosarcoma), and positive of CD 117. According to the size of tumor and number of segmentation nuclei in histology, biology action of most GISTs can be diagnosed correctly. According to the expression of c-kit, GISTs and other mesenchymal tumors of the gastrointestinal tract (leiomyoma, leiomyosarcoma, neurilemoma, neurofibroma, and so on) can be distinguished. At present, surgery is still the best choice in the clinical treatment, and many people consider unanimously that excising lies in completeness, not cleaning up large-scale, because this disease hardly occurs the metastasis of lymphnodes.