Immunohistochemical expression of CD117 and CD34 as stem cell markers in intradermal nevi, dysplastic nevi, and malignant melanomas

Abstract

BackgroundThe potential role of stem cells in neoplasia is a subject of recent interest. Cancer stem cells are able to proliferate and self-renew extensively because of their ability to express antiapoptotic and drug resistant proteins, thus sustaining tumor growth. Therefore, the strategy to eradicate cancer stem cells might have significant clinical implications. ObjectiveThe aim of this study was to assess the immunohistochemical expression of both CD117 and CD34 as stem cell markers in intradermal nevi, dysplastic nevi, and malignant melanoma (MM). Patients and methodsThe present study included a total of 38 patients; 11 patients with intradermal nevi, nine patients with dysplastic nevi, and 18 patients with MM (12 primary, four metastatic, and two recurrent). Using immunohistochemistry, we studied CD117 and CD34 in the tissue of all studied patients. ResultsIntradermal nevi were all negative for CD117, whereas dysplastic nevi showed 100% positivity and MMs showed 83.3% positivity. There was statistically significant difference between intradermal nevi and both dysplastic nevi and MMs, but no significant difference was found between the last two in CD117 expression. Intradermal nevi were completely negative for CD34 expression, the dysplastic nevi showed positivity in 6/9 (66.7%) patients and MM showed expression in 2/18 (11%). There was a statistically significant difference between intradermal nevi and both dysplastic nevi and MMs and between the last two in terms of CD34 expression. Conclusion CD117 could be considered as an indicator of malignant proliferative process. It could further be a useful marker to differentiate completely benign nevi from malignant melanocytic lesions. This may have therapeutic implications as a molecular target, which needs further investigations. CD34 neither has a role as a stem cell marker nor is a potential target for clinical trials with monoclonal antibody therapy in MMs.