Comparing the clinical, histopathological and myoepithelial features of estrogen receptor positive and negative mammary carcinomas.

OBJECTIVE The purpose of this study is to examine the relationship between hormone-receptor status and histological parameters, considering that some estrogen receptor (ER)-negative breast carcinoma are suggested to be of myoepithelial origin or differentiation; and to examine the presence of significant difference by myoepithelial markers and define their morphologies. METHODS For this research, 30 estrogen receptor-negative and 31 estrogen receptor-positive breast carcinomas diagnosed at the Pathology Department, Istanbul Training and Education Hospital, Istanbul, Turkey, between February 2003 and October 2004 were considered and compared clinically, microscopically and immunohistochemically considering myoepithelial markers using SMA, S100, keratin14. RESULTS We found a higher amount of grade 3 frequency pushing margins, solid islets, and presence of central necrosis in the estrogen receptor-negative group than in the positive group (p<0.001 and p<0.05). Six estrogen-negative and 2 estrogen-positive cases were found positive for myoepithelial markers; a difference which is non-significant (p=0.147). The presence of solid islets, fusiform, and clear cells was detected higher in myoepithelial positive tumors than in negative group (p<0.05). CONCLUSION For daily pathologic applications, some morphological properties of a breast carcinoma can give clues about ER and myoepithelial features. In estrogen receptor-negative tumors, there is a remarkable myoepithelial marker positivity. Studies involving broader series and different myoepithelial markers could give more reliable results.