Sentinel Lymph Node Biopsy
A sentinel lymph node biopsy is a diagnostic procedure that is often performed along with breast cancer surgery, such as a lumpectomy or mastectomy, to check for cancerous cells in the lymph nodes in the underarm area (axillary lymph nodes). Because lymph drains directly from the breast to the axillary lymph nodes, these small filtering tissues are usually the first to be affected by breast cancer spread. Those located closest to the tumor are known as the sentinel nodes.
The renowned team in Tampa General Hospital’s Cancer Institute and Breast Cancer Center are continually working to develop new ways to prevent and detect early-stage and locally advanced breast cancer. Ranked among the top 10% of hospitals in the U.S., TGH has earned the “High Performing in Cancer” designation from U.S. News & World Report for 2022-23. We are also proud to be accredited by the Commission on Cancer (CoC).
What Does a Sentinel Lymph Node Biopsy Involve?
A sentinel lymph node biopsy generally includes the following steps:
- Tracer injection – A tracer substance is injected into the affected breast near the tumor. The tracer—which may be a blue dye or a fluorescent, magnetic or low-dose radioactive compound—enters the lymphatic system and travels to the axillary lymph nodes.
- Sentinel lymph node identification – By using a special device (gamma probe) to observe which lymph nodes absorb the tracer first, the surgeon identifies the sentinel nodes.
- Sentinel lymph node removal – The surgeon removes the sentinel nodes (usually one to five) through the lumpectomy or mastectomy incision or a small incision in the underarm area.
- Sentinel lymph node assessment – The removed tissues are sent to a lab, where a pathologist examines them under a microscope to check for cancerous cells. A lab test known as H&E staining is frequently used for lymph node assessment.
If no cancerous cells are found in any of the sentinel lymph nodes, lymph node involvement—and cancer spread—is unlikely. Otherwise, further evaluation or treatment may be necessary. Some follow-up options include radiation therapy to the axillary lymph nodes and an axillary lymph node dissection, which involves removing and testing more lymph nodes from the armpit.
What to Expect With a Sentinel Lymph Node Biopsy
After a sentinel lymph node biopsy, some patients experience pain, swelling, bruising and/or numbness at the biopsy site. Additionally, if a blue dye tracer was used during the procedure, the dye may remain visible under the skin for a few months and the urine may have a bluish tinge for a few days. In most cases, any side effects of a sentinel lymph node biopsy are minor and short-lived.
Sometimes, however, a sentinel lymph node biopsy can affect lymph drainage and cause lymphedema, a long-term condition characterized by tissue swelling in the armpit. Therefore, persistent or severe swelling should be promptly discussed with a physician.
How Effective Is a Sentinel Lymph Node Biopsy?
The sentinel lymph node biopsy procedure is well established for evaluating breast cancer spread to the axillary lymph nodes. If there is cancer in the sentinel lymph nodes, this procedure will detect it in most cases.
Before the sentinel lymph node biopsy procedure became available, a more invasive procedure known as an axillary lymph node dissection was used in its place. An axillary dissection involves removing the pad of fat from the hollow of the armpit, which contains most or all of the axillary lymph nodes. Current research studies indicate that removing more axillary lymph nodes does not improve outcomes for patients with early-stage breast cancer. Therefore, the more extensive procedure is usually not used as a first-line diagnostic tool, but it may be considered after a sentinel lymph node biopsy, fine needle aspiration, core needle biopsy or imaging scan reveals suspicious or cancerous cells.
Benefit From World-Class Care at TGH
If you were recently diagnosed with breast cancer, it is important to find out whether the cancer has spread. Armed with this knowledge, your physician can plan the best course of treatment for you. If would like to discuss a sentinel lymph node biopsy with a breast cancer specialist at TGH, contact us at (800) 844-4554 to request an appointment.