DIAGNOSTIC DIFFERENTIATION BETWEEN AMELOBLASTOMA AND AMELOBLASTIC CARCINOMA: IMMUNOHISTOCHEMICAL STUDY

Introduction:Ameloblastoma (AB) is the commonest benign odontogenic tumor, while Ameloblastic Carcinoma (AC) is a malignant odontogenic tumor with metastatic potential. Diagnosis is challenging due to similar clinical and radiological features. Immunohistochemical (IHC) studies have been conducted to understand how these two tumors behave. Neural stem cells were found to be crucial in cell proliferation and epithelial-mesenchymal interactions during odontogenesis. They are also involved in the oncogenic processes, contributing to the aggressive behavior of some odontogenic tumors. Nestin is a neural stem cell marker which is expressed in teeth germ, mature teeth, and odontogenic tumors. Therefore, investigating its immunohistochemical expression may help to differentiate AC from AB. Objectives: study aims to quantify the immunoexpression of Nestin (via calculating area percent and optical density) in AB and AC. Material and Methods:Thirty-eight specimens of Ameloblastic tumors (19 AB and 19 AC) were obtained either from fresh biopsies performed in Oral & Maxillofacial Department or from previously diagnosed cases in Oral Pathology Department, Faculty of Dentistry, Alexandria University. Histopathological examination was done to confirm diagnosis. Clinical and radiographic data were collected for the cases. Then, immunohistochemical assessment of Nestin was performed in AB and AC. The results were tabulated and analyzed using the most appropriate statistical analysis test.Results: Specimens of AC demonstrated significantly increased expression of Nestin (57.24 % area percent & 145.96 mean optical density), in comparison to AB (20.47 % area percent & 52.19 mean optical density). Conclusion:Nestin may play an important role in differentiating AB from AC.