Gastrointestinal Stromal Tumor:a Clinicopathological Study of 50 Cases

Objective:To explore a clinicopathological and immunohistochemical features of gastrointestinal stromal tumor(GIST).Methods:50 cases of GIST were studied by histological evaluation along with an immunohistochemistry panel including CD117,CD34,SMA and S-100.Clinicopathological correlation was performed in 17 cases of GIST that had accompanied with the available follow-up data.Results:Among 50 GISTs,The patient's age ranged from 34 to 83 years(mean 59.2 years),with 37 males and 13 females.Histologically,the tumors composed of either spindle or oval to round cells arranged in interlacing fascicles forming whorls or cellular clusters,cytoplasm generally abundant and eosinophilic.There were 42 cases of spindle cell type,2 cases of epithelioid cell type and 6 cases of mixed cell type.Immunohistochemically,39 cases of GIST were positive for CD117 in a cell membranous pattern,In addition,36 GISTs were also positive for CD34,9 cases positive for SMA and 6 cases positive for S-100.According to the Lewin's Scheme,GISTs in this study were divided into 3 subcategories including groups of GIST(13 cases),of potential malignant GIST(14 cases)and of malignant GIST(23 cases)respectively.Kaplan-Meier survical analysis of 17 GISTs whom had been followed up for 10~42 months not showed a statistically significant difference present among the subcategories(P=0.361 3).Conclusion:GIST is the common mesenchymal tumor with special immunophenotype.The immunohistochemistry is useful for differential diagnosis.