- Good prognosis - 70-90% 10YS
- Histological type determined by architectural pattern
- Tubular 2-3%
- Low grade
- May be increasing with screening
- Cancer invades in small tubules lined by single layer of well-diff cells
- Mucinous 2-3%
- Low grade
- Usually post-menopausal women
- Bland tumour cells float like island in pools of mucin
- Medullary (‘Basal like’) 5%
- High grade, triple negative in appearance but not behaviour! = Behavioural paradox!
- Large tumour cells, very undifferentiated with pleomorphic nuclei. With dense lymphocyte infiltrate and syncytium appearing sheets of tumour cells
- Doesn’t tend to spread to lymph nodes or metastasis
- Tubulolobular
- Papillary
- Micropapillary (6%)
- Very high risk – 80-100% LN involvement and high risk of metastatic disease
- Cribriform
- Squamous carcinoma
- Rarer types; adenoid cystic carcinoma, adenomyoepithelioma