Sentinel lymph nodes: removal and biopsy


Results of biopsy of the sentinel lymph node

The result of biopsy of the sentinel lymph node can be negative or positive.

  1. Negative sentinel lymph node: the tumor is not present in the lymph node. No other lymph glands are removed.
  2. Positive sentinel lymph node: The sentinel lymph node biopsy indicates that the cancer has developed inside the sentinel lymph node and may be present in other nearby lymph nodes (called regional lymph nodes) and possibly in other organs. You can remove other lymph nodes in this area.
Normal biopsy of the sentinel lymph nodeAbnormal biopsy of the sentinel lymph node
  • The dye or marker flows evenly to the sentinel lymph node.
  • The lymph node has a normal number of lymph node cells.
  • The structure of the lymph node and cells are normal.
  • No tumors detectable. It is possible that the patient has a benign tumor in an organ.
  • The dye or marker does not flow evenly to the sentinel lymph node.
  • The sentinel lymph node cannot be identified.
  • You can see tumor cells. The tumor cells can originate from the lymph node, as in Hodgkin’s lymphoma.
  • The tumor cells can spread or metastasize to other locations, such as breast cancer or melanoma.






In the biopsy of a sentinel lymph node, less tissue is taken, but this is analyzed in more detail, unlike a standard lymph node dissection.

  • If there is a tumor, several surgeries may be required to control the other lymph nodes.
  • Swelling around the treated area is less common with sentinel lymph node biopsy than with lymph node dissection.
  • The dye methylene blue can turn the skin blue for several days after the biopsy. The urine may turn green over 1 or 2 days.
  • It is possible that from the small tissue sample, a biopsy of the sentinel lymph node will give a false negative result.

Surgery for breast cancer: quadrantectomy

There are two types of intervention:

Mastectomy: provides for the complete removal of the mammary gland body. Then a breast prosthesis is inserted, which shows a good cosmetic result.

Quadrantectomy: an operation in which a “quadrant” (about a quarter) of the breast is removed, including the tissue surrounding the malignant tumor. It is also called a partial or segmental mastectomy.

  • This reduces the risk of abnormal cells remaining in tissues and spreading locally or to other locations in the body (a process called metastasis).
  • As a rule, the distance is about a quarter of the breast size (hence “quadrant” in quadrantectomy).
  • Then the remaining tissue is reconstructed to minimize the aesthetic defects and sutured.
  • One can insert temporary drains under the skin to drain excessive fluid from the surgically treated area.
  • In some patients, lymph nodes under the arm (called axillary lymph nodes) may be removed on the same side of the tumor.
  • You should remove as few lymph nodes as possible, because if too many of them are removed, it will lead to serious complications, for example, lymphedema of the arm.
  • The surgeon sutures the wound with absorbable stitches that do not need to be removed.

In most patients, no recurrence of the cancer occurs after:

  • quadrantectomy,
  • Radiotherapy.

One study followed patients over the 20-year period after conservative breast surgery and showed that only 9% had recurred the cancer.

Risks of biopsy of the sentinel lymph node

After removal of the axillary lymph nodes:

  • the risk of lymphoedema is about 25%,
  • there is a 20% risk of an abnormal skin reaction (e.g. loss of sensitivity).
  • About 17% of women who have undergone conservative breast surgery have a poor aesthetic outcome (for example, asymmetry or distortion of shape).
  • The risk of complications from general anesthesia is less than 10%.

Complications of sentinel lymph node

As a rule, biopsy of a sentinel lymph node is a safe method, but like any surgical procedure, complications can occur, such as:

  1. Bleeding;
  2. pain and bleeding in the biopsy area;
  3. Formation of adhesions
  4. Infection;
  5. allergic reaction to the dye used in the procedure;
  6. Lymphedema: a condition in which the lymphatic channels are unable to drain the lymph from a region of the body, resulting in lymphatic congestion and swelling.

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