Gastric stromal tumors. Presentation of two cases with immunohistochemical study. Review of the literature

GSTs are uncommon mesenchymal tumors of the stomach. The evaluation of malignancy is difficult and their histogenesis is controversial. Recently a relationship to the pacemaker interstitial cells of Cajal (ICC) has been suggested because GSTs, like the ICC express CD117 (C-KIT protein). Some authors, like Miettinen in one of his studies, consider the CD117 positivity as part of the definition of GSTs. The purpose of this paper is to present two cases of GST with immunohistochemical study confirming the diagnosis of GST; the immunoreactivity of these two tumors is positive for CD117 and negative for protein S-100, actine and desmin. A review of the clinicopathologic, the immunohistochemical features, the prognostic factors and novelties in treatment will be presented.