The term breast cancer actually refers to a number of different forms of cancers that are associated with the breast tissue. The most common type of breast cancer is called invasive (or infiltrating) ductal carcinoma. Carcinoma is a medical term for cancer of the skin or tissues under the skin, such as the tissues lining or covering body organs.
Breast cancer starts in either the milk ducts in the breast (ductal carcinoma) or the milk-producing lobules (lobular carcinoma). The pathologist can tell the difference by looking through a microscope at a slice of the tumor removed by the surgeon.
If the tumor is still in the ducts or lobules, it is called in situ. If it has spread outside of those structures, it is called infiltrating or invasive. Therefore, a cancer which started in the milk ducts and has spread to tissues outside of the duct is called invasive ductal carcinoma.
Main types of breast cancer:
- ductal carcinoma in situ (DCIS)
- lobular carcinoma in situ (LCIS)
- invasive (infiltrating) ductal carcinoma (IDC)
- invasive (infiltrating) lobular carcinoma (ILC)
Your doctor will confirm the type of cancer you have after receiving the pathology report.