Imatinib mesylate in clinically suspected gastric stromal tumors

Gastrointestinal stromal tumors （GISTs） occur most frequently in the stomach.Diagnosis of gastric GIST is not always clear before surgery.Flexible endoscopy may suggest the nature of the lesion （a bulky tumor with preserved mucosa）; however,biopsy is rarely diagnostic.Therefore,diagnostic medication with safe drugs may provide a feasible way under such conditions after an informed consent is obtained.Based on the excellent efficacy of imatinib mesylate （IM） in the treatment of GIST,we successfully applied it in the diagnostic medication of two patients with clinically suspected gastric stromal tumors.In conclusion,the diagnostic medication with IM can be an alternative option for patients with suspected GIST that can not be confirmed pathologically.

A clinicopathologic and immunohistochemical study of gastrointestinal stromal tumors based on 122 cases

Objective:The aim of the study was to review the clinical records of 122 patients with gastrointestinal stromal tumors(GISTs) and analyze their clinicopathologic and immunohistochemical characteristics.Methods:The medic records of 122 patients with GISTs during the periods from January 2002 to May 2010 were reviewed.All tumors were confirmed by histological and immunohistochemical analyses.Results:The tumors occurred in 59 males and 63 females,ranging from 25 to 77 years.Of all cases,46 cases originated from stomach,42 from small intestine,17 from colon and rectum and 9 from retroperitoneal cavity and 4 cases from extra-gastrointestinal site.Liver was the most common organ that tumors metastases involved.Immunohistochemically,there were 114 tumors being positive for CD117 while 8 tumors negative for it.The frequencies of CD34 positive were higher in the stomach and rectum(89.1% and 86.7% respectively) than in the small intestine(64.3%,P < 0.05).Higher expression of SMA was in the tumors located in small intestine(54.8%) while the expressions of SMA in the gastric and rectal tumors were relatively low(21.7% and 20.0% respectively,P < 0.05).Conclusion:Gastrointestinal stromal tumors can occur in the gastrointestinal tract as well as in the extra-gastrointestinal sites.The frequencies of CD34 and SMA expression vary significantly with different locations.