Breast Carcinoma: Pathology

Key points

• • Most breast cancers arise from the lining of the ducts or the lobules, and are divided into non-invasive (in situ) and invasive types.
• • Invasive ductal carcinoma is the commonest type and often forms a hard, irregular, gritty mass on cut section.
• • Spread is to the axillary lymph nodes first and later to bone, lung, liver and brain through the blood.
• • Tumours are tested for oestrogen and progesterone receptors and for HER2, which show how the cancer is likely to behave and respond to therapy.
• • Warning features include a painless lump, skin dimpling, nipple retraction and, in inflammatory cancer, a red swollen breast resembling infection.