Article Type

Original Article


Oral Pathology


Objective: To disclose the variation in EZH2 expression among the different grades of MEC and to analyze the marker's immunohistochemical (IHC) expression in relation to the clinicopathologic data of all cases. Material and methods: The present study was conducted on 15 blocks diagnosed as MEC including equal numbers of different grades. These blocks were selected from the archives of the Oncology Center, Mansoura University. The specimens embedded in the retrieved paraffin blocks were all fixed in 10% formalin. Sections of 4 microns’ thickness intervals were serially cut and prepared for the EZH2 staining. Chi-square, Monte Carlo, and Fisher Exact tests were used for statistical analysis. Results: The parotid gland was the most affected site (66.7%). The age of patients ranged from 20 to 80 years with a mean of 58.3 years and slight female predominance. Stage III was the most frequent stage (40%) followed by stage IV (26.7%). Most MEC cases (73.3%) showed positivity to the EZH2 reaction. There was a statistically significant difference between histopathological grades regarding patients' ages (p< 0.05). There was a statistically significant difference between age groups regarding expression scores (p< 0.05). No statistically significant difference was observed among the different histopathological grades of MEC regarding EZH2 expression. Conclusions: EZH2 was expressed in most of the studied MEC cases, particularly the high-grade cases. Overexpression of EZH2 in MEC cases with nodal metastasis and histological invasions could predict a poor prognosis of the tumor.