Breast cancer typing and malignancy are as follows: 1. Typing: According to the WHO histological classification, breast cancer can be divided into two categories: non-invasive breast cancer and invasive breast cancer. Non-invasive breast cancer includes ductal carcinoma in situ and lobular carcinoma in situ, while invasive breast cancer includes invasive ductal carcinoma, invasive lobular carcinoma, medullary carcinoma, papillary carcinoma, inflammatory breast cancer and so on. Among them, invasive ductal carcinoma is the most common, accounting for about 65-80%, while the rest are called special types of breast cancer.2. Malignancy: Invasive breast cancer is more malignant than non-invasive breast cancer, and inflammatory breast cancer is the more malignant among invasive breast cancers. Inflammatory breast cancer is a relatively rare type of breast cancer, but it is highly invasive, with high metastasis, recurrence rate and relatively low disease-free survival rate, so it has received wide attention in recent years.