Understanding Lymph Nodes
Lymph nodes are small, bean-shaped glands that are part of the body’s immune system. They filter lymph fluid, which circulates throughout the body. Lymph nodes contain specialized immune cells that fight infections and identify foreign substances.
The lymphatic system maintains fluid balance and supports immune defense. As lymph fluid moves through lymphatic vessels, it collects waste products, bacteria, and damaged cells. This fluid then passes through lymph nodes, where these materials are filtered out and immune cells neutralize threats.
Quantity and Distribution in the Breast Region
In the breast region and surrounding areas, several groups of lymph nodes are particularly relevant. These include the axillary, internal mammary, and supraclavicular lymph nodes.
The axillary lymph nodes, located in the armpit, are the most prominent and typically number between 20 and 40. These nodes receive a significant portion of the lymphatic drainage from the breast, particularly from the outer quadrants.
Beyond the axilla, internal mammary lymph nodes are situated inside the chest, near the breastbone. While less numerous than axillary nodes, they are important because they drain lymph from the inner parts of the breast. Supraclavicular lymph nodes, located above the collarbone, also play a role in breast lymphatic drainage. The exact count of lymph nodes can vary from person to person, and factors like prior surgeries can influence the number found during medical procedures.
Lymph Nodes and Breast Health Significance
The status of lymph nodes in the breast region holds importance in breast health, especially concerning breast cancer. They act as indicators for determining if cancer cells have spread beyond the primary tumor.
When cancer cells break away from the breast tumor, they often travel through the lymphatic system and can become trapped in nearby lymph nodes. The presence of cancer cells in lymph nodes affects the staging of breast cancer, which is a system used to describe the extent of the disease. If cancer is found in these nodes, it typically indicates a more advanced stage of the disease, influencing treatment decisions and prognosis. For instance, the number of involved lymph nodes directly impacts the cancer’s N-stage in the TNM (Tumor, Node, Metastasis) staging system.
To assess lymph node involvement, a common diagnostic procedure is the sentinel lymph node biopsy. This procedure identifies and removes the first few lymph nodes to which cancer cells are most likely to spread from the primary tumor. A surgeon injects a tracer material, such as a radioactive substance or blue dye, which travels to these sentinel nodes, allowing them to be identified and removed for pathological examination.
If the sentinel nodes are free of cancer, it suggests that the cancer has likely not spread to other lymph nodes, potentially allowing for less extensive surgery. However, if cancer is detected in these nodes, further evaluation or treatment may be necessary to address potential wider spread.