Clinical and pathological features of gastrointestinal stromal tumors:a report of 39 cases

Objective: To explore clinical and pathological features of gastrointestinal stromal tumors(GISTs) and to probe the key points of diagnosis and differential diagnosis.Methods: The GISTs clinical features and pathological morphological changes of 39 cases from March 2006 to December 2009 in our hospital were analyzed retrospectively.HE staining method and immunohistochemical method were used to investigate CD117,CD34,S-100 and SMA.Results: Among the 39 cases,12 cases were of potentially malignant,10 cases were of low degree malignant,17 cases were of high degree malignant.The diameters of potentially malignant tumor were less than 3 cm without different types of cells,and with rare nuclear fission.And no obvious hemorrhage and necrosis occurred.Malignant tumor group showed hemorrhage,necrosis,rich cell,clear atypia and more common mitotic.Immunohistochemical test showed tyrosine kinase receptor CD117-positive,bone marrow stem cell antigen CD34-positive in 29 cases,soluble acidic protein S-100 positive in 8 cases,smooth muscle actin SMA-positive in 13 cases.Conclusions: CD117 and CD34 are the most valuable immune markers in diagnosing GIST.The degree of GIST malignant tumor closely correlates with the size,cell atypia,necrosis and mitotic number.The extent of malignancy increases when the proliferation Ki-67 index of the cell gets higher.