Potential immmunohistochemical markers to characterize epithelialmesenchymal transition in Pleomorphic adenoma
Anju Devi, Achla Bharti Yadav, Mala Kamboj, Anjali Narwal, Vinay Kumar and Virender Singh
Backgound: The histogenesis process of pleomorphic adenoma (PA) of salivary gland continues to remain a controversial subject. In this neoplasm, transition occurs from an epithelial or myoepithelial cell to a stromal element and is called an epithelial-mesenchymal transition (EMT) resulting in heterogeneity. The present research was aimed to study the morphological characteristics of varied components and epithelialmesenchymal transitions in PA using histopathological and immunohistochemical (IHC) analysis.
Materials & methods: For this purpose 15 PAs cases were selected from the archives and from each case of PA and 5 cases of normal salivary gland, five additional sections were cut from each for immunohistochemical analysis using E- cadherin, vimentin and α-actin. The numbers of immunoreactive cells were semiquantitatively measured and also determined the intensity of the immunostaining reaction.
Result: Immunohistochemically, as the cells transitioned from the lumial cells to descrete/detached cells of ductal structures, the percentage of positive cells tends to decrease for E- cadherin and increases for vimentin and actin. Additionally, neoplastic cells towards the periphery of ducalcystic structures or completely detached cells in the stroma showed intense to moderate positivity for vimentin and alpha smooth muscle actin (α-SMA). Chondroid/ hyalinized or myxoid stroma showed variable staining with these markers.
Conclusion: Our study provides the evidence that epithelialmesenchymal transition process represent the basic principle of the tisuse heterogeneity in pleomorphic adenomas.
Keywords: histogenesis, pleomorphic adenoma, transition, heterogeneity, immunohistochemical