Abstract
Heat shock protein 70 as immunohistochemical marker in odontogenic cycts The present work was conducted on 34 different odontogenic cysts. Seven cases were radicular, 16 developmental, and 11 infected developmental cysts. They were subjected to routine H&E, and immunohistochemical stain to evaluate the expression of HSP-70 in these different cysts. Results indicated statistical significant overexpression of HSP-70 in all radicular cysts and areas of inflammation of infected developmental cysts, as compared to developmental cysts and areas of non inflammation of developmental cysts. Lesions in the age group between 20-30years revealed highly significant expression of HSP-70 (radicular and infected developmental cysts). Concerning the cellular localization of HSP-70 immunopositivity in epithelial cells, most cases showed nuclear and cytoplasmic localization, few cases showed nuclear, cytoplasmic, as well as membranous localization. Both infected developmental cysts and non-inflamed areas of developmental cysts were characterized by immunopositive staining reaction in all layers. Radicular cysts, on the other hand, showed suprabasal expression in areas of mature cyst wall whereas the expression involved all layers in areas of intense inflammatory infiltrate. The inflammatory infiltrate was positive as well, in all cases. The neoplastic parts of developmental cysts: dentigerous, calcifying odontogenic tumor (CCOT), and keratocystic odontogenic tumor (KCOT), were stained positively in all layers, with membranous expression in the CCOT and KCOT. For CCOT, the keratinized, ghost cells were also positive. In case of mural and luminal ameloblastic differentiation of dentigerous cysts, all layers were positive, as well as the ameloblastic tissue