Evaluation of immunohistochemical expression of E-cadherin in pleomorphic adenoma and adenoid cystic carcinoma

BACKGROUND: Pleomorphic adenoma (PA) and adenoid cystic carcinoma (ADCC) are benign and malignant salivary gland tumors, respectively, with distinct behavior. They have similar origins and cell components. E-cadherins are the main homophilic cell adhesion molecules, which play a central role in maintaining epithelial integrity, functioning in intercellular adhesion and differentiation. Hence, changes in E-cadherin function are reflected in the morphologic events associated with the cellular arrangement, movement and wound healing. AIM: To study and compare the expression of E-cadherin immunostaining in PA and ADCC. MATERIALS AND METHODS: Fifteen cases of each PA and ADCC were immunohistochemically stained with E-cadherin. Five cases of normal salivary gland tissues were taken as the positive control. Mann–Whitney U-test was used for statistical analysis. RESULTS: About 86.6% of PA cases showed homogeneous staining. 66.6% of cases of ADCC showed heterogeneous staining. PA, cribriform and tubular patterns of ADCC predominantly showed moderate immune-staining and solid patterns of ADCC exhibited predominantly mild immunostaining. Depending on the intensity of staining, we found a significant P value between PA and the solid variant of ADCC. CONCLUSION: E-cadherin proved to be a better marker for epithelial phenotypes in PAs. In ADCC difference in staining intensity between different histological subtypes suggests that further studies should be done to assess the usefulness of an immuno-marker to know the aggressive behavior of ADCC.