31st December 2024

Pathology of breast cancer

Histological types of invasive breast cancer include ductal carcinoma (most common), lobular carcinoma, mixed ductal/lobular carcinoma, sarcoma (e.g. angiosarcoma), and lymphoma. Metastases in the breast most commonly arise from a breast primary. ‘In situ’ disease, as in ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS), refers to a non-invasive tumour confined to the basement membrane which has the potential to become invasive.

Breast cancer metastasis is usually initially by lymphatic invasion of the axillary, supraclavicular and, less often, the internal mammary lymph node chains. Common sites of breast cancer metastasis include bone, brain, liver, lung, lymph nodes and skin.