the study of cd117 expression in glial tumorsand its relationship with the tumor-type and grade

background : cd117 is a thyrosin kinase receptor encoded by c-kit proto-oncogene. it is expressed during normal development in some tissues and also in a subset of neoplasia especially gastrointestinal stromal tumors   (gists). treatment with thyrosin kinase inhibitors (e.g., imatinib) is useful in cd117- positive gists. the goal of this study is to investigate the expression of cd117 in glial tumors as a potential diagnostic marker and target for therapy. methods : in this descriptive-analytical study, paraffin- embedded tissue blocks from 50 cases of glial tumors (various histological types and grades) were selected in a convenience sampling for the cd117 immunhistochemical study including expression of the marker, staining intensity, and percentage of the stained cells. the results were analyzed by chi-square and mann–whitney tests. results : cd117 expression was detected in about 76% of glial tumors but the frequency of the expression showed no statistically significant relationship with the tumor type (p = 0.829). although cd117 immunoreactivity was more frequent   in high-grade tumors   (84%) compared   to the low-grade ones (68%), no statistically significant relationship was found between the cd117 expression and grade of the tumor (p = 0.09). staining intensity and percentage of stained cells in high-grade tumors were significantly more than in low-grade tumors (p-values of 0.046 and 0.023, respectively). conclusions : according to the statistically significant difference in the staining intensity and percentage of the stained cells between the low-grade and high-grade glial tumors, these two parameters may be useful for making distinction   between various grades of these tumors. moreover, according to the prominent expression of cd117 in high-grade gliomas, these tumors   may be potential candidates for treatment with thyrosin kinase inhibitors. keywords : cd117, glial tumors, immunohistochemical staining, tumor grade