Breast cancer occurs when one type of cell in breast tissue transforms from a normal cell into a cancerous cell. Every year, 192,000 woman and 2,000 men are diagnosed with breast cancer in the U.S., according to the National Cancer Institute. Just as there are several types of cells within the breast, there are several types of breast cancer cells.
Lobule Cells
The American Cancer Society reports that lobule carcinoma cancer cells first grow in the lobules of the breast, which is the tissue that produces breast-milk in women. The lobules contain many glands that produce the milk, and it is these glandular cells that transform into cancer in lobule carcinoma. Lobule carcinoma may be "in situ," meaning the cancer has not spread beyond the lobules, or "invasive," meaning it has spread beyond the lobules and are found among the other types of breast cells.
Ductal Cells
This type of breast cancer cell belongs to the most common type of breast cancer, ductal carcinoma. The cells that become cancerous in ductal carcinoma are the ones that line the ducts of the breast, according to the American Cancer Society. Each breast has ducts that allow breast milk to travel from the milk-producing lobule to the nipple. When it is the cells of the ducts that become cancerous, the result is ductal carcinoma. Analagous to lobular carcinoma, ductal carcinoma in situ means that the cancerous cells are only in the duct, and have not spread to the surrounding tissue. Invasive ductal carcinoma is diagnosed with the cancer cells have grown and spread through the wall of the duct, and into the breast tissue.
Connective Tissue Cells
Breast sarcoma is a classification that includes a few different types of cancerous cells that make up the connective tissue in the breast. Phyllodes tumor is one type connective tissue cell cancer, according to the Mayo Clinic. The American Cancer Society notes that phyllodes tumors are sometimes malignant, meaning they can be cancerous. Angiosarcoma is another example of a breast sarcoma, which begins in the cells lining the blood or lymph vessels.
