Gastrointestinal stromal tumors: Pathology and prognosis at different sites

摘要: Gastrointestinal (GI) stromal tumors (GISTs) are the most common mesenchymal specific to GI tract, generally defined as KIT (CD117)-positive with a characteristic set of histologic features. These tumors, derived from Cajal cells or their precursors, commonly occur at age >50 years in stomach (60%), jejunum and ileum (30%), duodenum (4-5%), rectum (4%), colon appendix (1-2%), esophagus ( 5 per 50 HPFs >5 cm diameter have high risk for metastasis. In contrast, all intestinal GISTs independent mitotic rate least moderate metastases, mitoses metastases. Intestinal ≤5 low Gastric can be divided into subgroups including 4 spindle cell epithelioid variants. histologically more homogeneous group often contain distinctive extracellular collagen globules, skeinoid fibers. Immunohistochemical demonstration KIT, CD34, protein kinase theta positivity helps properly identify these tumors.