OBJECTIVE: To investigate the clinicopathological and prognostic significance of the c-kit protein in gastrointestinal stromal tumor (GIST). METHODS: Paraffin embedded materials from 53 benign GISTs, 13 potentially malignant and 55 malignant cases were analysed for c-kit expression by immunohistochemical method, while using leiomyomas and schwannomas as controls. Positive signals were shown in cytoplasma and cell membrane. RESULTS: Of 122 GISTs, 118 (97%) were positive for c-kit. Localization of positive signals was accurate. The rate of c-kit protein in benign, potentially malignant and malignant cases was 98% (53/54), 93% (12/13), 96% (53/55) respectively. Compared with benign GIST, the positivity of c-kit in metastasis or recurrent cases decreased, but c-kit protein expression rate was not significantly different between the three patterns of GIST (chi(2) = 1.167, P > 0.05). Leiomyomas and schwannomas were typically c-kit negative. CONCLUSION: As a sensitive and specific marker of GIST, c-kit seems to be a useful antibody in the diagnosis and differential diagnosis of GIST, but it may not be used as a prognostic index.
OBJECTIVE: To investigate the clinicopathological and prognostic significance of the c-kit protein in gastrointestinal stromal tumor (GIST). METHODS:Paraffin embedded materials from 53 benign GISTs, 13 potentially malignant and 55 malignant cases were analysed for c-kit expression by immunohistochemical method, while using leiomyomas and schwannomas as controls. Positive signals were shown in cytoplasma and cell membrane. RESULTS: Of 122 GISTs, 118 (97%) were positive for c-kit. Localization of positive signals was accurate. The rate of c-kit protein in benign, potentially malignant and malignant cases was 98% (53/54), 93% (12/13), 96% (53/55) respectively. Compared with benign GIST, the positivity of c-kit in metastasis or recurrent cases decreased, but c-kit protein expression rate was not significantly different between the three patterns of GIST (chi(2) = 1.167, P > 0.05). Leiomyomas and schwannomas were typically c-kit negative. CONCLUSION: As a sensitive and specific marker of GIST, c-kit seems to be a useful antibody in the diagnosis and differential diagnosis of GIST, but it may not be used as a prognostic index.