Differentiation of odontogenic keratocyst from radicular and dentigerous cysts by bcl-2 protein - An immunohistochemical study

Aim: To analyze the bcl-2 protein expression in the epithelial lining of the Odontogenic keratocyst (OKC), Radicular (RC), and Dentigerous cysts (DC). Materials and Methods: Forty-five archival samples of paraffin-embedded tissue sections were utilized. Fifteen OKCs, 15 DC, and 15 RC were immunohistochemically analyzed for immunoreactivity of the bcl-2 protein. Results: Expression of bcl-2 was seen in the basal layer of the epithelial lining of the OKC. DC and RC showed almost complete negativity for bcl-2. There was a statistically significant increased expression in all OKCs. Conclusion: The bcl-2 protein overexpression could increase the survival of the epithelial cells and this increased lifespan could in turn, lead to the peculiar aggressive growth pattern of OKC. However, the bcl-2 staining can be useful to differentiate OKC from other odontogenic cysts.