Breast cancers can start from different parts of the breast. Most breast cancers begin in
the ducts that carry milk to the nipple (ductal cancers). Some start in the glands that make
breast milk (lobular cancers).There are also other types of breast cancer that are less
common.
A small number of cancers start in other tissues in the breast. These cancers are called
sarcomas and lymphomas and are not really thought of as breast cancers.
Although many types of breast cancer can cause a lump in the breast, not all do. There
are other symptoms of breast cancer you should watch out for and report to a health care
provider.
It’s also important to understand that most breast lumps are not cancer, they are benign.
Benign breast tumors are abnormal growths, but they do not spread outside of the breast
and they are not life threatening. But some benign breast lumps can increase a woman's
risk of getting breast cancer. Any breast lump or change needs to be checked by a health
care provider to determine whether it is benign or cancer, and whether it might impact
your future cancer risk. For more information see “What are the risk factors for breast
cancer?” and Non-cancerous Breast Conditions.