Ductal carcinoma forms in the lining of a milk duct within your breast. The ducts carry breast milk from the lobules, where it's made, to the nipple.
Ductal Carcinoma In-Situ (DCIS)
DCIS is a type of early breast cancer that starts and remains confined to the layer of cells where it began inside of the ductal system. It is the most common type of non-invasive breast cancer. Non-invasive means that the cancer has not spread beyond the ducts into the surrounding breast tissue. The cancer has remained in-situ which means "in its original place."
DCIS is not life-threatening, but having DCIS can increase the risk of developing a new breast cancer or invasive breast cancer later on in life. Most recurrences of breast cancer happen within five to 10 years after initial diagnosis. The chances of a recurrence are under 30 percent.
About 1 in 5 new breast cancer cases will be DCIS. Nearly all women diagnosed at this early stage of breast cancer can be cured. A mammogram is often the best way to find DCIS early.
Infiltrating (Invasive) Ductal Carcinoma (IDC)
IDC is the most common type of breast cancer. An invasive cancer is one that has already grown beyond the layer of cells where it started (as opposed to carcinoma in situ). This cancer forms in a milk duct, breaks through the wall of the milk duct and begins to invade the tissues of the breast. At this point, it may be able to spread (metastasize) to other parts of the body through the lymphatic system and bloodstream.
About 80 percent of all breast cancers are invasive ductal carcinomas. (Most breast cancers are invasive carcinomas - either invasive ductal carcinoma or invasive lobular carcinoma.)
This is a rare subtype of invasive ductal breast carcinoma. Tubular carcinoma cells have a distinctive tubular structure when viewed under a microscope. In this type of cancer, the tumor is usually small and comprised of cells that are low grade. “Low grade” means they look somewhat similar to normal, healthy cells and tend to grow slowly.
Tubular carcinomas account for about 2 percent of all breast cancers. They are treated like invasive ductal carcinomas but tend to have a better prognosis than most breast cancers. Tubular carcinoma of the breast is less likely to spread outside the breast than other types of breast cancer and is easier to treat.
The average age of diagnosis for tubular carcinoma ranges from the mid-40s to late 60s.
This carcinoma of the breast is a rare subtype of invasive ductal carcinoma, accounting for about 3 to 5 percent of all cases of breast cancer. It most frequently occurs in women in their late 40s and 50s and is called “medullary” carcinoma because the tumor is a soft, fleshy mass that resembles the medulla (gray matter) of the brain.
Medullary carcinoma cells are usually high grade in their appearance and low grade in their behavior. In other words, they look like aggressive, highly abnormal cancer cells, but they don’t act like them.
Medullary carcinoma doesn’t grow quickly and usually doesn’t spread outside the breast to the lymph nodes. For this reason, it’s typically easier to treat than other types of breast cancer.
This cancer has a rather well-defined boundary between tumor tissue and normal tissue. It also has some other special features, including the large size of the cancer cells and the presence of immune system cells at the edges of the tumor.
Mucinous Carcinoma (Colloid)
This carcinoma of the breast, also known as colloid carcinoma, is a rare form of invasive ductal carcinoma. Mucinous carcinoma of the breast accounts for about 2-3 percent of all breast cancer cases.
In this type of cancer, the tumor is formed from abnormal cells that “float” in pools of mucin, a key ingredient in the slimy, slippery substance known as mucus.
Normally, mucus lines most of the inner surface of our bodies, such as our digestive tract, lungs, liver and other vital organs. Many types of cancer cells, including most breast cancer cells, produce some mucus. In mucinous carcinoma, however, the mucus becomes a main part of the tumor and surrounds the breast cancer cells.
Mucinous carcinoma tends to affect women after they’ve gone through menopause. Some studies have found that the usual age at diagnosis is 60 or older.
Mucinous carcinoma is less likely to spread to the lymph nodes than other types of breast cancer making it easier to treat than more common types of invasive breast cancer.
Papillary Carcinoma of the Breast
Papillary carcinoma is often considered a subtype of ductal carcinoma in situ, and is treated as such. In rare cases, the tumor is invasive, in which case it is treated like invasive ductal carcinoma, although the outlook is likely to be better. These cancers tend to be diagnosed in older women who have already been through menopause, and they make up no more than 1 percent or 2 percent of all breast cancers.
An invasive papillary carcinoma usually has a well-defined border and is made up of small, finger-like projections.
On a scale of 1 to 3, with Grade 1 describing cancer cells that look and behave somewhat like normal, healthy breast cells, and Grade 3 describing very abnormal, fast-growing cancer cells, this cancer is often Grade 2, or moderate.