Joy Winter

Breast carcinomas present a heterogeneous group of tumours varying greatly with regard to histopathological classification, prognosis and treatment options. Recent research has identified a subtype of breast carcinoma that is associated with a poor prognosis and is most commonly found to be grade 3; these tumours are termed basal-like tumours due to their differentiation towards basal cell types.

Sixty cases of grade 3 ductal carcinomas not otherwise specified (NOS) were stained using immunohistochemical techniques with a panel of antibodies.

All cases were subjected to immunohistochemical and morphological analyses, and tumours were classified as either basal-like or ductal NOS.

Statistical analysis accompanied by sensitivity and specificity values showed cytokeratin 5 and vimentin to be the most useful antibodies for diagnosing the basal-like tumour. Morphological analysis found that a high mitotic count and presence of necrosis could be associated with the basal-like phenotype.

Results of this study have facilitated the development of an algorithm to allow identification and diagnosis of this tumour type.