2B5B
category
Gastrointestinal stromal tumour, primary site
Definition
This is the most common mesenchymal tumour that arises in the gastrointestinal tract. It is generally immunohistochemically positive for CD117 (KIT), phenotypically paralleling Cajal-cell differentiation, and most examples contain KIT- or PDGFRA-activating mutations. It is most frequent in the stomach and to a lesser degree in the small intestine. The prognosis depends on the tumour size and the mitotic activity.
4 subordinate codes
Nearby in Malignant mesenchymal neoplasms
2B50Chondrosarcoma, primary site2B51Osteosarcoma, primary site2B52Ewing sarcoma, primary site2B53Fibroblastic or myofibroblastic tumour, primary site2B54Undifferentiated pleomorphic sarcoma, primary site2B55Rhabdomyosarcoma, primary site2B56Angiosarcoma, primary site2B57Kaposi sarcoma, primary site