Lymph node excision for biopsy

Lymph nodes are small organs found throughout the body which play an important role in the immune system of our body. Lymph nodes may be as small as the head of a pin or as large as a bean. Lymph nodes swell when any infection or disease occurs in some part of the body near the lymph nodes. Lymph nodes are found isolated or in groups. Main groups of link nodes are found in the neck, the armpit and the groin areas.

The most probable lymph node in a group of lymph nodes to which cancer may spread first is known as the sentinel lymph node. There can be more than one sentinel nodes in some cases. Cancers like melanoma spreads to different parts of the body. These are called secondaries. If migration of the cancer to the lymph nodes has been suspected your doctor may suggest that a biopsy may be performed for ascertaining this matter. There are two types of biopsies. They are fine needle biopsy and sentinel node biopsy.

Fine needle biopsy

This is a very easy method for pathological diagnoses. If a lymph nose is suspected to be the sentinel lymph node in a group of lymph node and if that node is palpable, your doctor may stabilize it with his fingers. Then a needle will be passed to the node and cells will be collected from the node.  By examining this specimen in a microscope, the existence of cancerous cells in that lymph node can be ascertained. Stains with specific antibodies can be used to improve the correctness of the diagnosis.

Sentinel node biopsy:  Sentinel node biopsy is used for melanomas which are thicker than 1 mm. In this procedure a substance which has mild radioactivity property is injected to the skin of the patient around the melanoma. The radioactive substance spreads inside and gets into the sentinel lymph node. This procedure helps to identify the sentinel lymph node which can be excised and examined in a laboratory to see whether there are any cancerous cells. The sentinel biopsy procedure consists of three distinct parts which are detailed below.

1)      Lymphoscintigram: This procedure is usually done on the previous day of the operation. A small quantity of radioactive substance is injected to the skin near the melanoma. After this the patient is allowed to lie down for 2 to 3 hours under the scanning machine. Scanning of the patient in different angles and different positions using different technologies are done so that the exact position of the sentinel node can easily be identified by the surgeon.

 2)  Intraoperative lymphatic mapping with blue dye:   In this procedure when the patient is under anesthesia a blue dye is injected to the area near the melanoma. This spreads to sentinel lymph node. This helps the surgeon to identify the sentinel node through appropriate imaging technology.

 3)   Sentinel lymph node dissection: 

The dissection of the sentinel lymph node is done at the time of removal of the cancerous cells in the body of the patient. Removal sentinel node/nodes help to overcome the possibility of spreading of the disease to other parts of the body as secondaries.