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The above is not applied clinically. A panel of [[immunostains]] (ER, PR, HER2, EGFR, CK5/6) can reproduce the molecular groupings.<ref name=pmid19704256>{{Cite journal | last1 = Tang | first1 = P. | last2 = Skinner | first2 = KA. | last3 = Hicks | first3 = DG. | title = Molecular classification of breast carcinomas by immunohistochemical analysis: are we ready? | journal = Diagn Mol Pathol | volume = 18 | issue = 3 | pages = 125-32 | month = Sep | year = 2009 | doi = 10.1097/PDM.0b013e31818d107b | PMID = 19704256 }}</ref> | The above is not applied clinically. A panel of [[immunostains]] (ER, PR, HER2, EGFR, CK5/6) can reproduce the molecular groupings.<ref name=pmid19704256>{{Cite journal | last1 = Tang | first1 = P. | last2 = Skinner | first2 = KA. | last3 = Hicks | first3 = DG. | title = Molecular classification of breast carcinomas by immunohistochemical analysis: are we ready? | journal = Diagn Mol Pathol | volume = 18 | issue = 3 | pages = 125-32 | month = Sep | year = 2009 | doi = 10.1097/PDM.0b013e31818d107b | PMID = 19704256 }}</ref> | ||
Basal-like breast cancer | |||
*Overview | |||
**A type of breast cancer that is defined by expression of basal markers (CK14, p63, calponin, SMA) | |||
**Not derived from myoepithelial cells, merely express a phenotype more in keeping with basal cells than ductal cells | |||
**Most triple negative (ER, PgR, Her-2); therefore cannot be treated with the usual therapeutic agents | |||
**There is an association in young women between basal-like breast cancer and BRCA mutation | |||
*Classic Morphological clues: | |||
**Relatively circumscribed | |||
**Geographic necrosis | |||
**Abundant mitoses | |||
*However, this molecular group includes a variety of phenotypes including: | |||
**Medullary carcinomas | |||
**Medullary-like carcinomas - tumors with some, but not all, the histologic features of medullary carcinomas | |||
**Metaplastic carcinomas | |||
**High grade invasive ductal carcinoma of no special type | |||
*Behaviour | |||
**Basal-like breast cancer is a heterogeneous group | |||
**The behaviour of basal-like breast cancer appears to fall into two groups: | |||
***The tumours that do not metastasise have a better prognosis than other grade 3 IDC | |||
***Tumours with early metastasis – greater tendency to metastasise to visceral sites associated with poorer prognosis (such as lung and brain) instead of to nodes and bone | |||
Triple Negative Breast Carcinomas | |||
**Triple-negative and basal-like phenotypes are not synonymous but overlap (60–90% of triple-negative tumours are basal-like) | |||
**The classic phenotype of a triple negative tumor includes high histological grade (particularly high mitotic count), circumscribed edge, central fibrosis, necrosis, prominent lymphocytic infiltrate, syncytial growth and spindle cells. | |||
==Immunostains for typing and diagnosis== | ==Immunostains for typing and diagnosis== |
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