What Causes Lymphoma of the Skin?

Some risk factors can make a person more likely to get lymphoma of the skin, but it’s not always clear exactly how these factors might increase risk.

Scientists have learned how certain changes in the DNA inside normal lymphocytes (immune system cells) might cause them to become lymphoma cells. DNA is the chemical in each of our cells that makes up our genes, which control how our cells function. We usually look like our parents because they are the source of our DNA. But DNA affects more than just how we look.

Some genes control when our cells grow, divide into new cells, and die at the right time:

• Certain genes that help cells grow, divide, or live longer are called oncogenes.
• Genes that help keep cell division under control or cause cells to die at the right time are called tumor suppressor genes.

Cancers can be caused by DNA changes that turn on oncogenes or turn off tumor suppressor genes.

Some people inherit DNA mutations (changes) from a parent that increase their risk of developing some types of cancer. But lymphoma of the skin is not one of the cancer types often caused by inherited mutations.

DNA changes related to lymphoma of the skin are usually acquired after birth, rather than being inherited. Some of these acquired changes may have outside causes (such as infections), but often they occur for no apparent reason. They seem to happen more often as we age, which may help explain why most types of skin lymphomas usually occur in older people.

Scientists are learning about the exact gene changes that cause skin lymphomas. But even though they have found some of these gene changes, they still do not know why these changes occur.

The immune system seems to play an important role in some skin lymphomas. People with weakened immune systems (such as people with acquired immunodeficiency syndrome (AIDS) and people who have had an organ transplant) seem to have a greater chance of developing skin lymphoma, but it’s not clear why.

Some types of infections might also raise the risk of skin lymphomas. This might be because the infections force the body’s immune system to constantly be active. As more lymphocytes are made to fight the infection, there is a greater chance that some of these cells will have DNA mutations in key genes, which might eventually lead to lymphoma. Researchers are still studying this.