1. Ductal carcinoma in situ (DCIS; also known as intraductal carcinoma) is a non-invasive or pre-invasive breast cancer.DCIS means that the cells lining the ducts have become cancerous. The difference between ductal carcinoma in situ and invasive carcinoma is that the cells do not spread (infiltrate) through the ductal wall into the surrounding breast tissue-because it has not yet infiltrated, DCIS does not spread (metastasize) outside the breast. DCIS is a precancerous lesion that can progress to invasive carcinoma in some cases, but there is no good way to predict which ones will continue to progress. DCIS is a precancerous lesion that can progress to invasive carcinoma in some cases. 2. Invasive ductal carcinoma (IDC) is the most common type of breast cancer. It originates in the ducts of the breast, breaks through the walls, and infiltrates the fatty tissue of the breast. Therefore, IDC can spread (metastasize) to other parts of the body through the lymphatic system or bloodstream. 3. Invasive lobular carcinoma (ILC) originates in the lobules of the breast. Similar to IDC, ILC can spread (metastasize) to other parts of the body. Similar to IDC, ILC can spread (metastasize) to other parts of the body. ILC may be more difficult to detect by mammography than IDC. 4. Inflammatory breast cancer is a rare type of invasive breast cancer. There is usually no visible lump. Instead, Inflammatory Breast Cancer (IBC) causes the skin of the breast to become red and hot, and may also thicken the skin of the breast, giving it an appearance similar to that of an orange peel – caused by the cancer cells blocking the lymphatic vessels. The diseased breast may become enlarged, hard, tender or itchy. In the early stages, IBC is often misdiagnosed as mastitis and treated with antibiotics, but after poor results, the diagnosis is confirmed when a biopsy reveals cancerous cells.IBC may be difficult to detect on a mammogram.IBC has a higher likelihood of metastasizing and has a poorer prognosis. 5. Paget’s disease of the nipple originates in the milk ducts and spreads to the skin of the nipple and then to the areola, the dark-colored area around the nipple. The nipple and areola often appear crusty, scaly, and red, bleeding or oozing, and may burn or itch. Paget’s disease is almost always associated with DCIS or IDC and often requires a mastectomy. If there is no lump in the breast tissue and the biopsy shows DCIS , there is no invasive cancer and the prognosis is usually good. If it shows invasive, the prognosis is poor. 6. Angiosarcomas arise from blood vessels or lymphatic vessels, rarely occur in breast tissue, and are usually a rare complication of radiation therapy. Hemangiosarcomas can proliferate and spread rapidly, and treatment is consistent with other sarcomas.