The microscopic study of lymph node tissue, the histology, is done using staining, fixing, and microscopic anatomy. Before nodes in the body were discovered and these methods were used to study them, the small bean size glands known as the nodes were hard at work, performing their tasks secretly.
The body is a mysterious thing that holds tightly to its secrets. Over time the medical community has uncovered and shed light on many of these secrets like how the immune system works and the part that lymph nodes play in it.
Among the most recent discoveries is the sentential lymph node that can help minimize the number of nodes that are removed when staging cancer.
Staining to Reveal the Secrets of a Lymph Node
When cancer is diagnosed testing is done to establish the stage of cancer, which is determined by finding out if the cancer has spread. Lymph nodes are the most likely place the cancer will spread and from there it may travel to other parts of the body. To discover the hidden highway that the cancer may travel, the following may be injected to the cancer areas during an outpatient procedure:
- Radiolabeled colloid
- Isosulfan blue
- Methylene blue
Mapping the lymph nodes in the area will reveal nodes that the cancer will go to. The injected material will be tracked by the radioactivity or by the color change when scanned. This mapping allows for the node that watches over the cancer to be located. Recently it was discovered there is a sentinel node and generally if there is no cancer in that one, no further lymph nodes will need to be removed and tested for cancer. This has reduced the number of nodes that are removed.
The procedure of removal is called a lymphadenectomy and once removed a biopsy will be done on the node to test for cancer cells. Fixation of the specimen allows future testing of the specimen.
Fixation and Microscopic Anatomy of Specimen to Reveal Secrets in the Future
Proper processing of a lymph node after removal is essential to accurately diagnosis and stage cancer. Proper fixation will preserve or harden the material close to the same condition it was in while in the body. B5 is the preferred fixative for nodes and allows for the necessary studies to be performed on them after the time of removal. Knowing the microscopic structures of the lymph nodes will be needed to determine any abnormalities in the node. Healthy and unhealthy nodes have their own unique structure. The following can cause unhealthy lymph nodes:
When lymph nodes are missing or damaged it can cause stress on the other nodes and prevent lymphatic fluid from flowing properly.
As the medical community discovers more with the advances in technology there will be more to learn about lymph nodes and the part they play in the immune system and the relationship with cancer.