Melanoma is an aggressive form of skin cancer. It arises because pigment cells have changed into cancer cells due to, for example, excessive exposure to the sun.
A melanoma can be detected or present at different stages. A melanoma can spread (metastasize) and then spread to lymph nodes or other organs and places in the body. Metastatic melanoma is always stage III or IV, depending on the size and location of metastasis. This file focuses in particular on melanoma that has spread to the lymph nodes. Lymph nodes are involved in all stage III melanomas.
Metastases to lymph nodes
Cells in the lymph nodes usually have the function of clearing up inflammation or making bacteria and viruses harmless. Sometimes cancer cells settle in the lymph nodes or the lymphocytes turn into cancer cells themselves. In the first case, the cancer cells have become detached from the original growth, for example because the body is trying to remove the cancer cells. They then passed through lymph vessels to nearby lymph nodes. For example, a melanoma on the arm may first spread to lymph nodes in the armpits because they are close by. When the lymphatic system spreads the cells further to other organs, we speak of stage IV melanoma.
The risk of metastasis in melanoma increases with deep and / or thick melanoma. Once melanoma cells are in the lymph nodes, you speak of a melanoma that has spread to the lymph nodes.
Read more about it here the treatment of melanoma that has spread to the lymph nodes.
Where are lymph nodes?
The lymph nodes are distributed in groups throughout the body. They are located:
- In the neck
- In the groin
- By the lungs
- In the armpits
- In the abdominal cavity
- Along the trachea
- In the pelvis
How does metastatic melanoma develop?
The skin consists of different types of cells, connective tissue and a fat layer. Pigment cells, also called melanocytes, usually protect the skin from damage from ultraviolet radiation, the radiation from the sun. Too much exposure to ultraviolet rays can damage the skin. This damage is also called mutation. A mutation in the skin can cause pigment cells to grow uncontrollably. This often results in a restless birthmark, which changes shape and / or color, for example.
In about half of the melanoma cases, the protein is BRAF (aka BRAF-gen) is damaged. There is then a BRAF mutation. This mutated protein stimulates the growth of malignant growths and is therefore also called oncogene. It is important to know whether a melanoma is caused by a BRAF mutation in connection with the correct treatment.
The normal BRAF protein is part of a network of different proteins, namely: RAS, BRAF, MEK1, MEK2 and ERK. Together these proteins stimulate cell growth in a healthy way. This is also referred to as the MAP-K signal path. In case of a mutation in the BRAFgene, the MAP-K signal path becomes abnormally active. Due to the mutation it activates BRAFgene itself and the other proteins as well. Unusual cell growth occurs, and this can result in melanoma.
Stages, diagnosis and treatment of melanoma
Melanomas are classified into stages after diagnosis. The types of stages give the doctor and the patient more insight into the prognosis and the treatment (s) to be chosen. You can read more about this on the following pages: