Ductal Carcinoma in Situ of the Breast
Supplemental Studies
Immunohistology
- Demonstration of myoepithelial cells can confirm the in situ nature of a process while their absence supports invasion
- We prefer to use both p63 and calponin on problematic cases
- A variety of markers have been used for myoepithelial cells:
Marker Sensitivity Specificity Calponin Excellent Very good p63 Excellent Excellent Smooth muscle myosin heavy chain Good Excellent CD10 (CALLA) Good Good High molecular weight cytokeratin Very good Poor Maspin Good Poor S100 Good Very poor Actin Good Very poor - E-cadherin appears to be a sensitive marker of ductal differentiation vs lobular differentiation; its utility in borderline lesions is currently uncertain
- Myoepithelial cells often cannot be demonstrated around the outside of papillary DCIS; however, papillary DCIS is not clinically an invasive carcinoma
- Endocrine DCIS is defined as >50% of cells reactive with chromogranin or synaptophysin