ABSTRACT
Background: Dentigerous cyst diagnosis is simple but several case reports have documented neoplastic changes arising from them. Ameloblastoma is a common benign Odontogenic tumor with an aggressive manner and a high rate of recurrence. Ameloblastic Carcinoma is the malignant counterpart of Ameloblastoma but usually difficult to be distinguished from each other’s. Hence, need for Immunohistochemical markers may help achievement of accurate diagnosis. Objectives: Evaluation of Epithelial and Stromal Syn1 expressions and their roles in tumorigenesis and biological behavior of Dentigerous cyst, Ameloblastoma and Ameloblastic Carcinoma. Methods: Tissue samples comprising of 54 archived histopathologically confirmed cases of (10 Dentigerous cysts, 29 Ameloblastomas and 15 Ameloblastic Carcinoma). The sections were subjected to Immunohistochemical staining according to a standard protocol using antibody to Syn1. Results: Stromal Syn1 expression was higher in Desmolpastic Ameloblastoma than other Conventional Ameloblastoma subtypes. Unicystic Ameloblastoma showed higher Stromal Syn1 than Dentigerous cyst. Ameloblastic Carcinoma showed the highest immune-reactivity to Stromal Syn1 than Conventional Ameloblastoma. While, Epithelial Syn1 immune-reactivity was weak. Conclusions: Desmoplastic Ameloblastoma behaves in a more aggressive manner than other subtypes.Stromal Syn1 are highly expressed in aggressive and malignant odontogenic tumors and could be used together as prognostic predictor tool for odontogenic tumors