[Gastrointestinal stromal tumours: clinico-morphological features, pathogenesis and modern treatment strategies]

Gastrointestinal stromal tumours (GIST) are the commonest mesenchymal tumours of gastrointestinal organs accounting for 1-3% of all gastrointestinal neoplasms and almost 5% of all soft tissue sarcomas. Most GIST (95%) express transmembrane receptor KIT or CD117, CD34 (70%), vimentin (80%), specific smooth muscle and neurogenic markers (with different frequency). Up to 85% of the stromal tumours have mutations in the KIT gene (exones 9, 11, 13, 17) and 3-18% in the PDGFRA (platelet-derived growth factor receptor-alpha) gene (exones 12, 14, 18). Mutations are absent in 5% of KITand PDGFRA genes. Mutational status, mitotic index, size and location of the tumour are the most informative criteria for the choice of treatment strategy and prognosis of the disease.