E-cadherin expression: a diagnostic utility for differentiating breast carcinomas with ductal and lobular morphologies.

Objectives: The objective of this study was to evaluate the diagnostic utility of the E-Cadherin (EC) expression in differentiating between an infiltrating ductal carcinoma (IDC) and an infiltrating lobular carcinoma (ILC), the two most common forms of invasive breast carcinomas.

Methods: The authors evaluated the E-Cadherin expression by doing immunohistochemistical studies of all the cases of invasive lobular carcinomas (ILC) which were diagnosed in the pathology laboratory during a 3 year period and they compared the expression of E-Cadherin in an equal number of invasive ductal carcinomas (IDC) of the breast.

Results: A moderate to strong inter-membranous E-Cadherin expression on immunohistochemistry was seen in all the cases of IDC, while only 1 case of ILC showed a moderate E-Cadherin expression. Hence, the E-cadherin expression can be reliably used as a marker to differentiate IDC and ILC. However, an aberrant cytoplasmic expression of E-Cadherin may be seen in some cases of ILC, which should be interpreted with caution.