A possible role of myofibroblast in biological behavior of odontogenic keratocyst and ameloblastoma: A comparative study

Introduction: Ameloblastoma is the second most common odontogenic neoplasm. Odontogenic keratocyst (OKC) is an aggressive cyst known for its rapid growth and its tendency to invade the adjacent tissues, including bone. Alpha-smooth muscle actin, is an isoform typical of smooth muscle cells (SMC) and present in high amounts in vascular SMC. Stromal myofibroblasts have the potential to facilitate progression of neoplastic epithelial lesions that could contribute to their biological behavior. Aim: The objective of the present study is to assess immunohistochemically the frequency of stromal myofibroblasts in OKC and ameloblastomas and to correlate the same with the behavior of these lesions. Materials and Methods: The study includes six cases of ameloblastomas and six cases of odontogenic keratocysts which were immunohistochemically analysed for alpha smooth muscle actin expression. Counts were performed with a Olympus microscope under 40× objective and four fields were chosen for each section. Each α-SMA-positive cell, excluding those surrounding blood vessels, was counted and the total number of positive cells for all four examined fields per case, was calculated. Results: Mean α-SMA positive cells per field in odontogenic keratocyst was six as compared with ameloblastoma showed slight higher expression of 08. Statistical Analysis: one-way ANOVA test, P value was found to be 0.07. Conclusion: The mean number of myofibroblast (MF) in ameloblastoma was higher than OKC. Thus, a positive link can be suggested, when more MFs are present in the stroma, a more aggressive behavior of the odontogenic cyst/tumor can be anticipated.