Tubular Carcinoma 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
- Estrogen receptor (ER) and progesterone receptor (PR) are important markers for directing therapy and determining prognosis
- Current consensus is that any level of positivity should be reported as positive
- Her2neu status can be determined by either immunohistology or by FISH
- The other technique can be used for borderline cases