By Rodney T. Miller, M.D.
On certain occasions, it can be difficult to distinguish lobular carcinoma and lobular carcinoma in-situ (LCIS) from ductal carcinoma and ductal carcinoma in-situ (DCIS). In this situation, immunostains for E-cadherin are very useful. E-cadherin has been found to be expressed in only 4% of invasive lobular carcinomas (1 of 27 cases), but in all of 43 cases of ductal carcinoma and DCIS.
Ecadherin also stains normal ductal epithelium, as well as normal myoepithelial cells that are associated with benign ducts and lobules.
In addition to E-cadherin, low molecular weight cytokeratin is advocated by some authors for use in distinguishing ductal from lobular proliferations. Low molecular cytokeratin staining has been described as resembling a “bag of marbles” in lobular proliferations, whereas ductal proliferations have a more cohesive immunostain appearance. We have evaluated both of these markers on numerous occasions at ProPath, and in our experience, Ecadherin immunostaining is substantially easier to interpret, and we do not believe that low molecular weight cytokeratin immunostaining offers any particular advantage over E-cadherin.
1. Acs G, Lawton TJ, LiVolsi VA et al: Differential Expression of E-cadherin in Ductal and Lobular Carcinoma of the Breast. Modern Pathology 13 (1): 17A (abstract #77), 2000.
2. Yaziji H, Lehr H-A, Folpe A, Gown AM: Qualitative and Quantitative Immunophenotypic Distinction between Ductal and Lobular Carcinomas. Modern Pathology 11 (1): 31A (abstract #162), 1998.
3. Lehr H-A, Folpe A, Yaziji H et al: Cytokeratin Immunostaining Pattern and E-cadherin Expression Distinguish Lobular from Ductal Carcinoma of the Breast. Am J Clin Pathol 114:190-196, 2000
Date of last revision: August 2000.