Heather W. Goff, M.D., M.P.H. Answers Questions On: Cutaneous Lymphoma

White blood cells produced in the bone marrow enter both the skin and the bloodstream – and we actually have about twice as many white blood cells in our skin than we do in our bloodstream at any given moment.

This is because when the body fights off bad things, it fights them first on our skin, before they get into our blood. That’s why we don't die from a paper cut.

After white blood cells are created in the bone marrow, they go through a maturation process and then travel to different parts of the body to live. Some go to live in the lymph nodes, some to the bloodstream, the lungs, the gastrointestinal tract, and other places – and some put down roots in the skin.

For reasons that aren’t understood, some of the white blood cells that travel to the skin can start dividing and growing uncontrolled on their own. When any cell does that without provocation, we call it a cancer. When it happens with the white blood cells in the skin, we call it a cutaneous lymphoma.

Cutaneous lymphoma usually appears as a rash, which is one reason it can be hard to detect and diagnose early on. For instance, the average patient with mycosis fungoides – the most common type of cutaneous lymphoma – waits about six years to be diagnosed with the condition.

And because the mature white blood cells that make up cutaneous lymphomas are very close cousins of normal white blood cells, affected areas on the skin often don't appear cancerous. The areas may look like eczema, psoriasis, or an allergic reaction, for example – and are often diagnosed and treated as such.

Patients are often correctly diagnosed by a dermatologist only after the affected areas don’t go away for years and years.

In general, worrisome conditions tend to stick around, while things that aren’t worrisome tend to go away on their own pretty quickly. Conditions such as eczema and psoriasis, for instance, are known to flare up and settle down, and harmless rashes come and go.

People with unexplained skin rashes should see a dermatologist when the rash lasts for a month or more.

It’s an exciting time with respect to understanding the genomics of cutaneous lymphoma. We're just starting to scratch the surface in terms of its genetic and immunologic underpinnings and the many types of genetic mutations the disease can involve.

In addition, UT Southwestern is helping to create an international registry for cutaneous lymphoma patients. Because cutaneous lymphomas are so rare, it’s hard to extrapolate meaningful information about the disease with only 100 patients at each treatment center.

By enabling clinicians around the world to gather and compile data, the registry will eventually contain information about tens of thousands of cases. This will allow us to understand a lot more about what's going on with patients, to better guide their treatments and better predict their outcomes.