The role of vascular endothelial growth factor in proliferation of odontogenic cysts and tumors: An immunohistochemical study

BACKGROUND: Vascular endothelial growth factor (VEGF) is capable of initiating angiogenesis in blood vessels and may act as mitogenic agent for epithelium of odontogenic cysts and tumors. This study was conducted to evaluate the role of epithelial VEGF expression in odontogenic cysts and ameloblastoma and its correlation with argyrophilic nucleolar organizer region counts to assess its role in their biological behavior. MATERIALS AND METHODS: In this retrospective cross-sectional study, 45 histologically confirmed cases, 15 cases of each of keratocystic odontogenic tumors (KCOTs), dentigerous cysts, and ameloblastomas were examined for immunohistochemical expression for epithelial VEGF, and argyrophilic nucleolar organizer regions (AgNORs) (used as secondary marker in this study) staining was done for comparing the proliferative capacity with VEGF. RESULTS: KCOT shows mild expression within the basal layers and strong expression in the suprabasal layer whereas, in dentigerous cysts, a majority showed no VEGF expression whereas ameloblastomas showed strong expression in all cases by stellate reticulum-like cells at the center of the follicles and suprabasal layers of epithelium. The results of AgNOR counts were higher in KCOTs as compared to ameloblastoma and least in dentigerous cysts. CONCLUSION: VEGF expression by the epithelium of odontogenic cysts and tumors may play a role in epithelial proliferation via autocrine mechanism as reflected by increased AgNOR counts. The angiogenic activity via paracrine pathway may be responsible for the difference in growth rate and neoplastic behavior of the lesions.