What is the Difference Between Sentinel and Axillary Lymph Nodes?

Sentinel lymph nodes and axillary lymph nodes are both involved in the assessment of breast cancer spread, but they differ in their role, location, and the procedures used to evaluate them.

Sentinel Lymph Nodes:

• These are the first lymph nodes to receive direct lymphatic drainage from the tumor.
• The sentinel lymph node is the closest node to the primary tumor.
• To identify sentinel lymph nodes, a radioactive tracer or blue dye is injected into the tumor area. The surgeon locates the sentinel nodes by looking for the lymph nodes that have absorbed the tracer.
• Sentinel lymph node biopsy (SLNB) is a standard procedure in patients with early-stage breast cancer who have clinically negative lymph nodes.

Axillary Lymph Nodes:

• These nodes are located in the underarm area.
• Axillary dissection removes more axillary lymph nodes than a sentinel node biopsy does.
• Axillary dissection is more likely to affect arm function and cause lymphedema compared to a sentinel node biopsy.
• If the sentinel node biopsy result is positive, a subsequent axillary lymph node dissection (ALND) may be required.

In summary, sentinel lymph nodes are the first lymph nodes that receive drainage from the tumor and are identified using a radioactive tracer or blue dye. Axillary lymph nodes are located in the underarm area and are removed through a more extensive procedure called axillary dissection. The choice between a sentinel node biopsy and axillary lymph node dissection depends on various factors, including tumor size, grade, and the patient's clinical condition.

Comparative Table: Sentinel vs Axillary Lymph Nodes

Here is a table comparing the differences between sentinel and axillary lymph nodes:

Sentinel lymph nodes are the first lymph nodes that cancer cells are likely to spread to, and they play a crucial role in determining the spread of cancer. Axillary lymph nodes, on the other hand, are located in the armpit and drain lymph from various areas of the body. Sentinel node biopsy is a less invasive procedure compared to axillary lymph node dissection, which removes more nodes and disrupts more normal tissue, increasing the risk of lymphedema.