The study of 13 cases of Gastrointestinal stromal tumors in Kerman

13 cases of  gastrointestinal stromal tumors (GIST) diagnosed in Kerman university hospitals between 1370-1376 are reviewed.of these cases,6 were male and 7 were female.patients, age ranged between 19 to 70 years with a median of 47.8 years. in 8 cases tumor developed in stomach and in 5 cases it originated from small intestine.all available H & E stained slides were reviewed and PAS and masson,s trichrome stains and immunohistochemical staining for smooth muscle actin and S-100 protein were performed.positive reaction was observed in 8 cases for actin and in 2 cases for S-100 protein.immunohistochemical findings did not corroborate primary histopathologic diagnoses in 7 cases.these findings confirm this notion that routine histopathologic stains are not reliable for diagnosis of line of differentiaton in GIST.moreover, median age of our patients are significantly lower than that of other studies(p<0.0005) but this needs further study.