Background: Odontogenic lesions range from simple cysts to benign tumors and carcinomas. Unicystic ameloblastoma is a monocystic lesion and a less aggressive tumor compared to multicystic ameloblastoma. Ameloblastic carcinoma is the malignant variant of the multicystic ameloblastoma and may arise de novo or from malignant transformation of a long-standing multicystic ameloblastoma.
Methods:We collected 54 tissue samples obtained from patients from 2000-2017 that were stored in the archives section of the Pathology Department of Taleghani Educational Hospital, Tehran, Iran. The specimens were processed for immunohistochemistry analysis. Immunostaining of the markers was assessed via quantitative methods. Statistical analysis was performed using one-way ANOVA and the chisquare test.
Results: One-way ANOVA analysis and the chi-square test did not reveal any statistically significant differences between the expression levels of endocan, ET-1, and ETAR and lesion type. A positive correlation existed between ET-1 and ETAR expression levels in unicystic ameloblastoma and multicystic ameloblastoma (Pearson’s r = 0.506, P<0.002), and between ET-1 and ETAR expression levels in unicystic ameloblastoma and ameloblastic carcinoma (Pearson’s r = 0.376, P<0.024).
Conclusion: This study revealed a positive correlation between the histological degree of lesion and endocan, ET-1, and ETAR expression levels. Hence, it might suggest that multicystic ameloblastoma develops from unicystic ameloblastoma. Over time, multicystic ameloblastoma may undergo a malignant transformation to ameloblastic carcinoma. Possibly, a simple cystic neoplasm can progress to a cystic lesion with invasion to the connective tissue wall and a gradual development into a true neoplasm (multicystic ameloblastoma), with potential for malignant transformation (ameloblastic carcinoma). Endocan, ET-1, and ETAR can be used as prognostic biomarkers for different variants of multicystic ameloblastoma and possible new targets for cancer therapy.