Mycosis Fungoides Health Article

Definition

Mycosis fungoides is a skin cancer characterized by patches, plaques, and tumors where cancerous T lymphocytes have invaded the skin.

Description

Mycosis fungoides, the most common type of cutaneous T-cell lymphoma, originates from a type of white blood cell called a T lymphocyte or T cell. In mycosis fungoides, cancerous T cells accumulate in the skin. These cells and the skin irritation they create become visible as growths or changes in the skin's color or texture.

Mycosis fungoides usually develops and progresses slowly. It often begins as an unexplained rash that can wax and wane for years. Whether this stage represents early mycosis fungoides or a precancerous stage is controversial. The classic symptoms of mycosis fungoides are red, scaly skin patches that develop into raised plaques, then into large, mushroom-shaped tumors. The patches often originate on parts of the body that are covered by clothing and sometimes improve when they are exposed to sunlight. Itching can be intense.

As the cancer progresses, the cancer cells lose their affinity for the skin and spread to nearby lymph nodes and other internal organs. The normal T cells also start to disappear. Because T cells are very important in immunity, this leaves the patient susceptible to infections. Treatment at an earlier stage of the disease can often stop or slow this progression.

Sézary syndrome is a variant of mycosis fungoides. Sézary syndrome is characterized by red, thickened skin and large numbers of cancer cells in the blood.

Demographics

Mycosis fungoides is usually diagnosed after the age of 50, but has been seen as early as childhood. Mycosis fungoides develops twice as often in men as in women and is more common in people of African than of European origin.

Causes and symptoms

Environmental chemicals, virus infections, allergies, and genes have all been suggested as possible causes of this cancer. As of 2001, there is little concrete evidence to favor any of these possibilities.

The symptoms of mycosis fungoides include:

• Patches: patches are red or brown, sometimes scaly, flat areas. There may be one patch or many. Patches may itch and can resemble psoriasis, eczema, allergies, or other skin diseases. Some patients do not have a patch stage.
• Plaques: plaques are red or brown, sometimes scaly, raised areas. Itching is usually more intense than during the patch stage. The hair sometimes falls out in the affected skin. If the face is involved, the facial features can change.
• Tumors: tumors can originate from plaques, red skin, or normal skin. They are usually reddish brown or purple. The itching can diminish, but the tumors may develop painful open sores or become infected. Some tumors can become very large. Patches, plaques, and tumors can co-exist.
• Erythrodermic form: in the erythrodermic form, the skin becomes red, thickened, and sometimes peels and flakes. The palms and soles thicken and may crack. Itching is usually intense. More than 90% of the time, the erythrodermic form is associated with Sézary syndrome.
• Other, more rare symptoms are also seen, including itching alone.