"Neuroectodermal influence of CD 99 immunoexpression correlates with the clinical behavior of odontogenic cysts and tumors".

Background: Odontogenic tumors show a variety of characteristic features that are dependent on the tumor cell origin and the stage of tumor cell differentiation. Odontogenic cysts arise from the enamel organ or remnants of dental epithelium which influences their pathogenetic model and further clinical behavior of these lesions. Aim: The study aims at assessment of CD 99 immunoexpression in odontogenic keratocyst (OKC) and ameloblastoma (in tooth bearing [anterior to third molar] and nontooth bearing areas [molar ramus area]) to postulate neural influence in their pathogenesis and the clinical behavior. Materials and Methods: Immunohistochemical analysis for CD 99 was performed on paraffin-embedded tissue sections on 50 histopathologically confirmed cases of OKC and ameloblastoma (25 each) arising within the oral cavity and were scored qualitatively, topographically, and according to cellular localization. Statistical Analysis: The resulting data were analyzed using the SPSS software version 20.0. The significance of the parameters was tested by the Pearson's Chi-square test (P ≤ 0.05 as statistically significant). Results: CD99 immunoreactivity was distributed in both tooth bearing and nontooth bearing groups of OKC and ameloblastoma with an increased immunoexpression in basal and suprabasal layers of OKC in nontooth bearing area and in peripheral cells of ameloblastoma in nontooth bearing area confined to the cell membrane. Conclusions: The results point toward the role of CD99 in the pathogenesis and aggressive behavior of such odontogenic lesions and it can be used as a promising therapeutic target.