Immunohistochemical evaluation of metallothionein, Mcm-2 and Ki-67 antigen expression in tumors of the adrenal cortex.

Background: The aim of this study was to assess the metallothionein (MT), maintenance protein 2 (Mcm-2) and Ki-67 expressions in adrenocortical adenomas and carcinomas in comparison to normal tissue and evaluate the correlations between these markers of proliferation and between these markers and tumor diameter.

Materials And Methods: The expression of MT, Mcm-2 and Ki-67 was assessed by immunochemistry in forty-eight adrenocortical adenomas, six adrenocortical carcinomas and eleven normal adrenal cortex tissue samples.

Results: The expressions of MT, Mcm-2 and Ki-67 in the adrenocortical carcinomas were significantly higher than in the adenomas and normal tissue (p<0.05). The levels of Mcm-2 were also higher in the adrenocortical adenomas compared to the normal tissue (p<0.05). The Mcm-2 expression showed a positive correlation to the expression of MT in the adrenocortical carcinomas (r=0.773; p<0.05) and to the expression of Ki-67 in the adrenocortical adenomas (r=0.432; p<0.05). The malignant tumor diameter was positively correlated with the MT and Mcm-2 expressions (r=0.766, p<0.05 and r=0.620, p<0.05, respectively).

Conclusion: The assessment of Mcm-2 expression seems to be of special importance as a marker of adrenocortical dysplasia and a reliable indicator of malignancy in suspicious masses of the adrenal cortex.