Abstract

ABSTRACT Ameloblastic fibroma (AF) is a rare odontogenic tumor which consist of neoplastic epithelial and mesenchymal tissues. There has been much debate and confusion regarding its nature and biological behavior. However, recent reports have suggested that this lesion has the potential for recurrence and malignant transformation. We believe that the best way to understand the behavior of tumors is to study them by means of molecular methods. To clarify the assumption whether there is a seemingly innocuous hamartomatous (AF) and a neoplastic (AF) of a more aggressive behavior, it was suggested in this work to compare the expression of molecular biomarkers Ki-67, MMP-9 and e-cad in selected cases of (AF) and their expression in ameloblastoma with its known aggressive nature, and Adenomatoid odontogenic tumor (AOT) with its slow benign course aiming to clarify the possible relation of these factors with the different biological and clinical behaviors of the lesions. Material and Methods:14 cases of AF, 17 cases of ameloblastoma and 8 cases of AOT were included in this study and immunohistochemically stained and evaluated for Ki-67, MMp-9 and e-cad. The results were assessed and statistically analysed. Results: For ki-67 there was a statistical significant difference between the three lesions (P<0.0001). (AB) showed statistical significance with (AF) and (AOT) while there was no statistical significance in ki-67 immunopositivity between (AF) and (AOT) (P=0.1165). For MMp-9, (AB) showed statistical significance of MMP-9 immuno-expression with (AF) and (AOT). There was also statistical significance immune-positivity of MMP-9 between (AF) and (AOT). E-cad immunoexpression showed no statistical significance in e-cad immuno-expression between (AB) and (AF) (P=0.3413), while there was a significant difference between (AB) and (AOT). Conclusion: AFs are true neoplasms with an indolent nature as shown by the close resemblance of expression of Ki-67, MMP-9 and e-cad to those expressed by (AOT) and the significant differences between it and (AB). The claimed tendency of AF to recur may be attributed to leaving out remnants of the tumor rather than an aggressive growing nature of the tumor itself or presence of 2 different variants of ameloblastic fibroma