ICD-11

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.

A gastrointestinal stromal tumour that arises from the small intestine. It usually affects adults over fifty years of age. The majority of cases have spindle cell morphology. The prognosis depends on the tumour size and the mitotic activity.