Document Type: Original Article

Authors

1 Dept. of Oral and Maxillofacial Pathology, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran

2 Dept. of Oral and Maxillofacial Pathology, School of Dentistry, Shahid Sadoughi Yazd University of Medical Sciences, Yazd, Iran

Abstract

Statement of Problems: Evaluating cytokeratin contents of odontogenic cysts and tumors can be one of the important aspects in comparative study of these lesionsPurpose: The aim of this study was to evaluate expression of CK13 and CK18 in odontogenic cysts and ameloblastomasMaterials and Methods: In this study, radicular cysts (20 cases), dentigerous cysts (20 cases), OKC (20 cases), unicystic ameloblastoma (20 cases) and solid ameloblastoma (20 cases)   were evaluated. Then, 3-4 sections were prepared and stained with immuhistochemical procedure (avidin- biotin method. The obtained data by microscopic consideration was analyzed with statistical tests such as: Chi-square, Mann-Whitney, Wilcoxon (p <0.05).Results: All of the odontogenic cysts and cystic parts of unicystic ameloblastoma expressed CK13 in the upper layers (middle and superficial) more than the deeper ones (basal and parabasal). In ameloblastomas, CK13 expression in stellate reticulum and acanthomatose component was more than preameloblasts. Expression of CK18 in the upper layers (middle and superficial) was more than deeper layers (basal and parabasal) in radicular and dentigerous cysts. Results of immunoreactivity with CK18 in OKC was negative in 100% of cases. In addition, ameloblastomas (unicystic and solid) did have not significant differences in expression of CK13 and CK18.Conclusion: CK13 did not show any differences between these lesions but significant difference in CK18 expression at all 4 layers of the epithelium in odontogenic cysts and ameloblastomas may indicate the different nature of these lesions and probably confirms this suggestion that unicystic ameloblastoma is initiated as a neoplasm essentially, no from neoplastic change of an odontogenic cyst, in particular dentigerous cyst. The same CK13 and CK18 expression pattern in unicystic and solid ameloblastomas reveals the same biomolecular nature despite different gross and clinical features.Key words: Radicular cyst, Dentigrous cyst, OKC, Ameloblastoma, Cytokeratin13, Cytokeratin18, Immunohistoch-emistry