Breast cancer can begin in different areas of the breast — the ducts, the lobules, or in some cases, the tissue in between. The diagram above shows the different areas of the breast and what they look like.
The most common types of breast cancer are Ductal and Lobular. Of these, Ductal is the most common, and accounts for 65% of all breast cancer seen. Ductal cancer can be low grade and slow growing or high grade and highly aggressive.
Ductal carcinoma in situ (DCIS) is the earliest stage at which breast cancer can be diagnosed. In situ means it is in the ducts where it originated and has not spread to the breast tissue outside the milk ducts. Experts believe that as many as 50% of people with DCIS will develop invasive breast cancer within ten years, so treatment and followup is imperative.
Lobular starts in the lobes and is nearly always low grade. It can be difficult to diagnose as the cancer sometimes is not seen on mammograms while on cytology it can look like a normal breast
Less common types are:
If you want to find out more about the different types of breast cancer, this is a good website to visit: http://www.breastcancer.org/symptoms/types