Understanding the Different Types of Breast Tumors: Benign vs. Malignant

The type of cancer that begins in the breast is known as breast cancer. It can develop in one or both breasts when cells start growing out of control. Although breast cancer is commonly associated with women, it can also affect men, although the percentage of male breast cancer cases is far less than breast cancer in women.

The majority of breast lumps are non-cancerous, or benign. Benign breast tumors are still abnormal growths but do not grow beyond the tissue of the breast. The good news about benign tumors is that they are not life-threatening. The bad news about them is that they can increase the risk of breast cancer development later. This is why it is vital to have any abnormal changes or breast lumps examined to determine if it is benign or malignant (cancerous). 

Breast Cancer – Where It Begins

The human breast is on the upper body and rests on top of the rib cage and chest muscles. The organ has two visible sections, the left breast, and the right breast and both are made of fatty tissue and contain ducts and glands. Female breasts produce milk and the size and shape of the breast results from the amount of fatty tissue they contain. 

Different types of breast cancer form in different parts of the breast. Here is a closer look at each of the parts of the breast and the type of cancer that can start there.

Lobules

These glands are responsible for the production of breast milk used to feed newborns and babies. Cancers that form here are lobular cancer.

Ducts

These tiny canals transfer breast milk to the nipple from the lobules that produce it. Of all breast cancers, this is where the majority of them start to develop. They are called ductal cancers.

Nipple

The small ducts join together and form larger ducts that end at the opening in the skin tissue called the nipple. This is where breast milk comes out of the breast. The darker and thicker skin that circles the nipple is the areola. The breast cancer that can develop in the nipple is called Paget disease of the breast and is a less common type of breast cancer.

Fatty Tissue

The breast lobules and ducts havey fat and connective tissue around them called stroma. It holds them in place and is where phyllodes tumor cancer can form. It is a less common type of breast cancer.

Blood/Lymph Vessels

Each breast contains blood and lymph vessels. A less common type of cancer called angiosarcoma forms in the lining of these vessels.

Other Breast Cancers

Some cancers can develop in other breast tissues. Although they are not normally considered breast cancers, they fall under the category because of where they occur. These cancers are called lymphomas or sarcomas. 

Breast Cancer – How It Spreads

When cancer cells enter either blood or the lymphatic system, they can be sent to other parts of the body beyond the breast where it first developed. The lymphatic system is a network of bean-sized glands called lymph nodes and organs, and ducts or vessels. All of these components work together to gather and transport clear lymph fluid to the blood. The lymphatic system is the main part of the body’s immune system that flushes away tissue waste and other matter. When cancer in the breast enters lymph vessels, it is carried away from the breast and is captured in lymph nodes where it can grow. This process can complicate treatment plans.

Where Breast Lymph Vessels Go

There are a few locations where lymph vessels drain and these are where many cancers spread. The primary sites are:

Axillary Lymph Nodes

These are the lymph nodes located under the arm

Internal Mammary Lymph Nodes

These are the lymph nodes inside the chest, close to the breastbone

Supraclavicular Lymph Nodes

These are the lymph nodes located above the collarbone

Infraclavicular Lymph Nodes

These are the lymph nodes located below the collarbone

When cancer cells move to lymph nodes, it means that the odds are higher that they went through the entire lymphatic system. The issue with that is those cancer cells may have spread elsewhere in the body. When this happens, it is said that the cells have metastasized. This does not mean that every instance of cancer cells flowing through the lymphatic system results in metastases. However, some women will develop metastases later even if cancer cells do not move to their lymph nodes. This is why it is so important for cancer patients to track their symptoms to assist with diagnosis.

Breast Cancer – The Different Types

The breast cells that are affected are what determines the specific type of breast cancer. As a result, this means that many different types of cancer can originate in the breast. The majority of them are carcinomas with ductal carcinoma in situ (DCIS) being the most common – cancer that forms in the ducts found within the breast. 

The most invasive of the breast cancer varieties are adenocarcinomas. Other kinds of breast cancers are angiosarcoma or sarcoma but since they begin developing in other breast cells, but are not true breast cancers. 

The proteins or genes that may be produced by the cancers are how they are classified. The classification process is fairly straightforward. Tumor cell samples are removed during a biopsy and tested for proteins. They are estrogen receptors, progesterone receptors, HER2 gene, or HER2 protein. The cancer cells also receive a grade. The resulting information, the proteins found in the cancer cells, and the tumor grade identify what stage the cancer has reached. This assists medical professionals in determining treatment plans. Improved outcomes result from early detection.

Final Thoughts

Breast cancer can start in many different parts of the organ which produces various types of cancers. Benign tumors (non-cancerous) don’t normally leave the breast where malignant cells (cancerous) can move into the lymphatic system or bloodstream and get transported to lymph nodes in other parts of the body. Sometimes cancer cells in lymph nodes will move to other body parts. Tests of cancer cells removed from the body (biopsy) determine the stage and grade of cancer which aids in the development of a treatment plan. Early detection is vital to identify cancer cell formation and is responsible for saving many lives.