Sentinel nodes are simply the first nodes draining a cancerous region. For breast cancer, they are usually located in the armpit. That's why healthcare providers test the sentinel nodes to see if cancer has spread beyond the original tumor.
How many sentinel lymph nodes are there?
In most cases, there are one to five sentinel nodes, and all are removed. The sentinel nodes are sent to a pathologist to examine under a microscope for signs of cancer. In some cases, sentinel node biopsy is done at the same time as surgery to remove the cancer.
Where is the sentinel lymph node in the breast?
The sentinel lymph node (SLN) is the underarm (axillary) lymph node closest to a breast cancer. During surgery to remove early-stage breast cancer, the sentinel node often is removed and sent to a pathologist who determines if there is cancer in it.
