Ls GIST: Definition Most frequent mesenchymal neoplasms in the Gl tract Highest incidence among group aged 50-65 years Up to 50%of GIST recur and/ or metastasize 5-years survival rate (historically)30 to 40% Up to 90%of GIST carry K/T or Pdgfra mutations 90% stain positive for KIT 1. Miettin en M et al. Virchows Arch. 2001: 438: 1-12 Courtesy W3 Hofmarin, Memmingen, Germany