A sentinel lymph node biopsy is a surgical procedure for individuals with breast cancer. It determines if cancer cells have spread from the primary breast tumor to the first lymph nodes that drain fluid from the tumor site. This helps healthcare providers understand the cancer’s spread, which is crucial for treatment planning. The procedure is generally safe, with most individuals recovering quickly.
The Role of Lymph Nodes in Breast Cancer
Lymph nodes are small, bean-shaped organs within the body’s lymphatic system, a network of vessels and tissues that remove waste and maintain fluid balance. These nodes play a role in the immune system, filtering lymph fluid and trapping harmful substances, including bacteria, viruses, and cancer cells. Hundreds of lymph nodes exist throughout the body, with a cluster in the armpit area, known as the axillary lymph nodes.
In breast cancer, cells can detach from the primary tumor and travel through lymphatic vessels to the nearest lymph nodes, where they may begin to grow. The “sentinel lymph node” refers to the first lymph node or group of nodes that receive lymphatic drainage directly from the tumor area. Examining these nodes helps determine the cancer’s stage and guides treatment decisions.
The Sentinel Lymph Node Biopsy Procedure
The sentinel lymph node biopsy procedure involves distinct steps to identify and remove the sentinel node(s). Before the surgery, a radioactive tracer, a blue dye, or both, are injected into the breast near the tumor. The radioactive tracer is injected a few hours before the biopsy, allowing it to travel through the lymphatic vessels to the sentinel nodes.
Following the injection, a specialized imaging scan called lymphoscintigraphy may be performed to visualize the lymphatic pathways and sentinel node locations. During the surgical procedure, often performed as an outpatient procedure under general anesthesia, a surgeon uses a handheld device called a gamma probe to detect the radioactive tracer. This probe emits an audible signal that strengthens as it nears the sentinel node(s).
The surgeon also looks for any lymph nodes that have turned blue from the injected dye. Once identified, a small incision is made, usually in the armpit, and the sentinel lymph node(s) are carefully removed. Typically, only one to three lymph nodes are removed, making this procedure less invasive than traditional extensive lymph node removal.
Understanding Your Biopsy Results
After the sentinel lymph node(s) are surgically removed, they are sent to a pathology laboratory for microscopic examination. A pathologist analyzes the tissue to determine if any cancer cells are present. Results are usually available within a few days to a couple of weeks, though preliminary results can sometimes be available on the same day.
A “negative” result means that no cancer cells were found in the sentinel lymph node(s). This suggests the cancer has likely not spread beyond the primary tumor site. In such cases, further extensive removal of lymph nodes, known as axillary lymph node dissection, is often not necessary, which can reduce potential complications.
Conversely, a “positive” result indicates that cancer cells were detected in one or more sentinel lymph nodes. This means the cancer has spread beyond the breast and into the lymphatic system. Depending on the extent of cancer found, additional treatment may be recommended. This could include further surgical removal of armpit lymph nodes, radiation therapy to the armpit area, or other systemic treatments.
Life After Sentinel Lymph Node Biopsy
Following a sentinel lymph node biopsy, individuals can expect a quick recovery, often returning to routines within 2 to 7 days. Discomfort at the incision site, which may include mild pain, bruising, or slight swelling, is common. These effects are usually temporary and can be managed with over-the-counter pain medication. The incision typically heals within about two weeks, and the resulting scar tends to fade over time.
Temporary numbness or a tingling sensation in the armpit or arm area due to nerve irritation during the procedure is common. This sensation usually improves over several months as the nerves heal. In some instances, a fluid buildup known as a seroma can occur at the surgical site, which often resolves on its own or may require drainage by a healthcare provider.
Lymphedema, which is swelling in the arm or hand caused by a buildup of lymph fluid, is a less common outcome after lymph node removal. While this can occur, the risk is generally lower with a sentinel lymph node biopsy compared to more extensive lymph node dissections, as fewer nodes are removed. Healthcare providers monitor for lymphedema and provide guidance to manage or prevent this condition.