Immunohistochemicai study of Ki- 67 expression in unicystic Ameloblastoma and Dentigerous cyst

Abstract

Statement of Problem: Differentiation of dentigerous cyst from unicystic ameloblastoma, discovering any initial ameloblastic changes in lining epithelium of dentigerous cyst at early stage, and differentiation between hyperplastic odontogenic epithelium in fibrous capsule of dentigerous cyst from ameloblastic proliferation, need to an accurate and reliable technique."nPurpose: The aim of this study was to determine and compare Ki-67 immunoreactivity in various locations of the epithelium of Dentigerous cyst and Unicystic Ameloblastoma."nMaterials and Methods: In this historical Cohort study, 15 cases of dentigerous cyst and 9 cases of unicystic ameloblastoma were selected. Immunohistochemistry staining was performed by M1B-1 (murine monoclonal antibody against Ki-67). The stained nucleous were counted in basal and suprabasal layer of lining epithelium of both lesions in 3000 epithelial cells. Finally, the percentage of positive cells (presented as labeling index) was calculated, t- student test was used to analyze the related data."nResults: Ki-67 (LI) in basal layer of Dentigerous cyst (2.59±1.66) and Unicystic Ameloblastoma (3.76±79) had no significant differences, but Ki-67 (LI) in suprabasal layer of unicystic ameloblastoma (2.15±0.69) was significantly higher than dentigerous cyst (0.77±0.55) P=0.003)."nThe difference between the average numbers of positive cells for Ki-67 (LI) in these two lesions was statistically significant (P<0.05) and it was higher in Unicystic Ameloblastoma than Dentigerous cyst."nConclusion: Based on the findings of this study, it is suggested that Ki-67 (LI) in suprabasal layer or throughout the epithelium can be considered as a useful marker for differential diagnosis between dentigerous cyst and unicystic ameloblastoma.

Keywords

• Ki-67 antigen
• Unicystic Ameloblastoma