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.