E-cadherin is a transmembrane glycoprotein that plays a key role in cell-cell adhesion in epithelial tissues (1-2). The adherens junction between epithelial cells is comprised of extracellular domains of E-cadherin from adjacent cells, which interact through a molecular zipper motif. In normal tissues, immunostaining of E-cadherin is localized to the membrane of epithelial cells, consistent with its role in cell adhesion.
In breast lesions, membranous expression of E-cadherin has been associated with ductal neoplasia, consistent with the intact adhesion complexes of this histologic subtype (1-2). In contrast, the loss of E-cadherin is typically observed in the majority of cases of lobular neoplasia; however, studies have shown that up to 20% of cases of lobular neoplasia continue to exhibit E-cadherin immunostaining (1,3-4).
Staining of p120 and E-cadherin has been shown to be complementary and an aid in the accurate categorization of ductal and lobular neoplasms, including the distinction between low-grade ductal/lobular carcinoma in situ and lobular neoplasia (2).
Normal breast or breast ductal cell carcinoma
1. de Deus Moura R, et al. Immunohistochemistry Applied to the Differential Diagnosis Between Ductal and Lobular Carcinoma of the Breast. Appl Immuohistochem Mol Morphol. 2012 May 16 Epub ahead of print.
2. Dabbs DJ, Bhargava R, Chivukula M. Lobular Versus Ductal Breast Neoplasms: The Diagnostic Utility of P120 Catenin. Am J Surg Path. 2007;31:427-437.
3. Sarrio D, et al. Cytoplasmic localization of p120ctn and E-cadherin loss characterize lobular breast carcinoma from preinvasive to metastatic lesions. Oncogene. 2004;23:3272-3283.
4. Mastracci TL, et al. E-cadherin alterations in atypical lobular hyperplasia and lobular carcinoma in situ of the breast. Mod Path. 2005;18:741-751.
5. Center for Disease Control Manual. Guide: Safety Management, NO. CDC-22, Atlanta, GA. April 30, 1976 “Decontamination of Laboratory Sink Drains to Remove Azide Salts.”
6. Clinical and Laboratory Standards Institute (CLSI). Protection of Laboratory workers from occupationally Acquired Infections; Approved guideline-Third Edition CLSI document M29-A3 Wayne, PA 2005.