Expression of EMP 1, 2, and 3 in Adrenal Cortical Neoplasm and Pheochromocytoma

The purpose of this study is to investigate the expression of the epithelial membrane proteins (EMP) 1, 2, and 3 in adrenal gland neoplasm and to explore the broader implications of this. Tissue microarrays were constructed for 132 cases of adrenal cortical neoplasms (ACN) (adrenal cortical adenoma (115 cases), and carcinoma (17 cases)) and 189 cases of pheochromocytoma. Immunohistochemical staining was performed to identify EMP 1, 2, and 3, and was compared with clinicopathological parameters. The H-score of EMP 3 (p < 0.001) was higher in pheochromocytoma when compared to that of ACN, and the H-score of EMP 1 (p < 0.001) and EMP 3 (p < 0.001) was higher in adrenal cortical carcinomas when compared to that of adrenal cortical adenomas. A higher EMP 1 H-score was observed in pheochromocytomas with a GAPP score =3 (p = 0.018). In univariate analysis, high levels of EMP 1 and EMP 3 expression in ACN were associated with shorter overall survival (p = 0.001). Differences were observed in the expression of EMPs between ACN and pheochromocytoma. EMPs are associated with malignant tumor biology in adrenal cortical neoplasm and pheochromocytoma, suggesting the role of a prognostic and/or predictive factor for EMPs in adrenal tumor.

Automated summary

The study investigates the expression of EMP 1, 2, and 3 in adrenal gland neoplasms and explores their broader implications. Immunohistochemical staining of tissue microarrays shows higher expression of EMP 3 in pheochromocytoma compared to adrenal cortical neoplasms, and higher expression of EMP 1 and EMP 3 in adrenal cortical carcinomas compared to adrenal cortical adenomas. High levels of EMP 1 and EMP 3 expression in adrenal cortical neoplasms are associated with shorter overall survival.