Sentinel node biopsy is a way of pinpointing the first few lymph nodes into which a breast tumor may spread (called the "sentinel" nodes). This helps doctors remove only those nodes of the lymphatic system that are most likely to contain cancer cells. Usually one to three lymph nodes are removed.

In breast cancer, the sentinel node is usually located in the axillary nodes, under the arm. In a small percentage of cases, the sentinel node is found somewhere else in the lymphatic system that drains the breast. If the sentinel node(s) show cancer cells, there may be other positive lymph nodes involved. If negative, it is highly likely that all of the upstream nodes are negative.

How is the sentinel node biopsy procedure performed?

To locate the sentinel node(s), a radioactive labeling substance, blue dye, or both, is injected into the area around the tumor before a mastectomy or lumpectomy is performed. The tracer travels the same path to the lymph nodes that the cancer cells would take. This makes it possible for the surgeon to determine the node(s) most likely to be the first nodes drained by the breast, by either visualizing the color or using a handheld Geiger counter.

What are the advantages of the sentinel node biopsy method?

Research suggests that the sentinel node biopsy procedure can be useful in determining which lymph nodes to remove, without the risk of complications associated with surgically removing all potentially cancerous nodes. Many women experience lymphedema (arm swelling), discomfort, and limited range of motion after having many of their axillary nodes removed, but sometimes this is necessary.


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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 11/4/2015..#9192