Aim: To study the expression of calretinin in odontogenic cyst as well as odontogenic tumor and correlate the importance of the calretinin in differentiating unicystic ameloblastoma from odontogenic keratocyst. Materials and Methods: 20 cases each of ameloblastoma, 20 cases of unicystic ameloblastoma, 20 cases of dentigerous cyst and 20 cases of odontogenic keratocyst was assessed using calretinin. Slides were made from the archival blocks of each case and were stained immunohistochemically with calretinin. Case history performa was filled from the previously recorded case. Results: Correlation between calretinin staining and histopathological diagnosis was done and it was found that all 20 cases of ameloblastoma showed positivity for calretinin whereas 17% out of 20 cases of unicystic ameloblastoma showed positivity for calretinin staining. All the cases of dentigerous cyst and odontogenic keratocyst were negative for calretinin. Thus there was a significant difference in the distribution of staining for calretinin in the different odontogenic cysts/tumors(chi square value= 69.742, p value<0.01. Conclusion: The expression of calretinin in ameloblastoma suggest specific immunohistochemical marker for ameloblastic epithelium and serve as an important diagnostic aid in differentiating cystic odontogenic lesions and ameloblastic tumors. It was found that unicystic ameloblastoma showed a focal distribution pattern for calretinin whereas in ameloblastoma both focal and diffuse patterns were observed.
Keywords- Calretinin, Odontogenic tumor, Unicystic Ameloblastoma.