What is a sentinel lymph node dissection?

A sentinel lymph node dissection, also known as a sentinel node biopsy or SNB, is a procedure that is used to determine if your breast cancer has moved into the lymph nodes. During a sentinel node biopsy, your surgeon will remove one to three axillary lymph nodes to evaluate if they contain cancerous cells and if so, what stage the cancer is in. If the lymph nodes that are extracted do not contain cancerous cells, then the remaining axillary lymph nodes are not likely to contain cancer cells.

A sentinel node biopsy is an alternative to an axillary lymph node dissection, which takes 10 or more lymph nodes to evaluate for cancer.

Who is a candidate for sentinel lymph node dissection?

Sentinel node biopsies are not options for every patient. The goal of the procedure is to limit the amount of surgery needed, but in some cases more surgery may be needed after a sentinel node dissection.

Candidates for a sentinel node biopsy include:

  • Patients who have more than one breast tumor
  • Women who have had previous breast cancer surgeries or an axillary lymph node dissection
  • Patients who have ductal carcinoma in situ (DCIS) that has been treated with a mastectomy. DCIS is a cancer where malignant cells are found in the breast milk duct lining
  • Women who have undergone neoadjuvant therapy (chemotherapy before surgery)

Patients who are not candidates include:

  • Women who have a cancerous tumor over 5 cm large and the cancer has spread extensively into the lymph nodes
  • Patients with DCIS that was treated with a lumpectomy
  • Pregnant women
  • Women with inflammatory breast cancer

It is important to have this procedure done with an experienced surgeon. Mercy Health surgeons have extensive training and experience performing this complicated procedure.

Benefits of sentinel lymph node dissection

Your surgeon only needs to remove one to three lymph nodes to determine if the breast cancer has spread to the underarm lymph nodes. Therefore, other healthy lymph nodes are not unnecessarily removed.

The procedure gives your doctor the information they need with the least surgery and risk. In addition, sentinel lymph node dissection is associated with lower risk of lymphedema (buildup of lymph fluid in the body’s soft tissues). Lymphedema commonly occurs in the breast or underarm and can cause numbness or weakness in the affected area.

What are the side effects of sentinel lymph node dissection?

Side effects of a sentinel node dissection include:

  • Seroma — lymph backup in the armpit
  • Numbness in the armpit or under the upper arm
  • Heightened sensitivity or discomfort in the area affected

What to expect during a sentinel lymph node dissection?

During a sentinel node biopsy, your surgeon will inject a harmless, radioactive dye into the breast — typically under the areola. Your Mercy Health surgeon will then make an incision under the arm to locate the lymph nodes that contain dye. Once the affected lymph nodes are located, your surgeon will remove them. The lymph nodes will be evaluated by a pathologist for signs of cancer.

Recovery from a sentinel lymph node dissection

While many women do not experience side effects after a sentinel node biopsy, some women have bruising or pain at the incision site and others feel fatigued. Your breast and under your arm may feel swollen for two to three days but will be back to normal within a week. Your incision site will take a couple weeks to heal, and the scar will fade over time.

It is important to closely follow your doctor's recovery instructions regarding how quickly you can return to your normal activity level, your diet, medication management, as well as care of your incision site.

Follow your physician's recommended follow-up schedule and call right away if you experience any severe side effects.

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