Mycosis fungoides

Early mycosis fungoides (MF) can look like eczema or psoriasis, so it can take a long time to diagnose. In an international registry of 348 people with early-stage MF, 86 in 100 had a delay, and the median time from first symptom to diagnosis was 3 years. There is no single test that proves MF, so doctors put several findings together.

Doctors take skin biopsies, and more than one may be needed over time. Lab tests on the skin sample look at the markers on the T cells (immunophenotyping). A T-cell receptor (TCR) gene rearrangement test checks whether large numbers of T cells share the same receptor. That points to one abnormal family of cells, called a clone.

Blood tests include a complete blood count and a count of lymphoma cells in the blood, called Sézary cells. Staging looks at the skin, lymph nodes, blood and internal organs. It may include a chest X-ray, CT or PET scans, a lymph node biopsy and a bone marrow biopsy. The Cutaneous Lymphoma Foundation stresses that a pathologist with expertise in skin lymphoma confirms the diagnosis.

Early treatment often acts directly on the skin, using topical corticosteroids or other medicines, phototherapy or localized radiation. Choice depends on the extent and character of the lesions and previous response.

More widespread or resistant disease may need systemic treatment, such as retinoids, interferon, targeted antibodies or other agents. Chemotherapy and clinical trials have roles in selected circumstances. The aim includes controlling symptoms and preserving quality of life as well as reducing lymphoma.

Allogeneic transplantation can offer durable remission and curative potential to selected patients with advanced disease. Because it carries substantial risks, it is not routine for early mycosis fungoides. Autologous transplantation does not provide the same donor immune effect and is not the standard transplant strategy here.

For most people, MF is a slow, long-lasting (chronic) condition. Most people are diagnosed at an early stage, when patches or plaques are limited to the skin, and very often it never spreads beyond the skin. The Cutaneous Lymphoma Foundation says most people diagnosed with MF live with early-stage disease and have a normal life span.

Stage is the main guide to outlook. The course is harder when MF forms tumors or reaches the lymph nodes, blood or internal organs. Other features linked to a harder course include age over 60, a high LDH blood test and large-cell transformation, when MF changes into a faster-growing lymphoma. In the folliculotropic type, lymphoma cells gather around hair follicles. It usually grows very slowly while it stays as early plaques, but it is serious once it spreads beyond the skin.

U.S. experts describe a donor (allogeneic) stem cell transplant as the only treatment available today that may cure MF. Because of its risks, it is kept for some people with advanced or hard-to-treat disease. European experts advise getting the disease under good control before a transplant. They also stress talking with a transplant team early, so a transplant can happen at the right time.