Generally we think of lymphoma as a blood cancer (like Hodgkins and non-Hodgkins disease)—diagnosable diseases from blood testing and lymph node involvement. Occasionally, the lymphomas may arise from primary skin disease. Such is the case with mycosis fungoides, which is more ominous than its name suggests. Mycosis fungoides in not a fungal disease as it sounds but a Cutaneous (skin) T cell lymphoma that actually begins on the skin.
Mycosis fungoides (MF) may involve the skin for years or even decades without a diagnosis being made. It begins as a local (or less commonly generalized) red patch or plaque that is usually identifiable on the trunk. The only presenting complaint to someone affected with it is most commonly itching. Early skin biopsies may not identify the disease until it is more advanced, and that can be up to 10 years after its appearance. Tumors appear in more advanced cases, and lymph node swelling also occurs in more progressive disease. Sometimes the lymph node swelling is benign and is from local pressure from the lesion on nearby nodes, but sometimes MF extends directly into the nodes by itself.
Skin biopsy is the usual means of diagnosis. Often a non-healing lesion is biopsied by the dermatologist, who has no idea that MF will be the diagnosis on pathology. The findings don’t spread to the bloodstream until more advanced disease occurs—the circulating T cells are called Sezary cells and are detectable in blood samples.
Mycosis fungoides is a difficult differential diagnosis for doctors, who may actually treat lesions with other causes in mind before a biopsy shows the definitive characteristics of the disease under the microscope. Psoriasis is one commonly confused disease. So are drug eruptions, eczema, and even ringworm. The only way to diagnose it is through an adequate biopsy of the lesion or lesions.
Treatment of mycosis fungoides is not only difficult but complex. Some cases are slowly progressive and in older individuals will not affect mortality. Early and even aggressive treatment doesn’t appear to prevent progressive disease. Corticosteroids are applied to the skin early, with medications such as mechlorethamine, bexarotene and ultraviolet phototherapy. As the disease becomes more relentless, PUVA therapy, interferon, interleukin, and even total skin electron beam treatments are used. Chemotherapy (like in more systemic lymphomas) is given if the disease does not respond to more local therapies or is quickly progressive.
Mycosis fungoides does take time to develop into a malignant and fatal disease, and not every case does. Those who have just patch or plaque involvement do better than those whose lymph nodes are involved early. Those with limited plaque disease do the best, and many times their eventual survival is not compromised. The disease is treated in these slower progressive stages because overly aggressive treatment early in disease doesn’t always influence prognosis and complications and premature death may actually befall the individual before the end stages of MF does.
Mycosis fungoides used to be a universally uninsurable disease, but that has changed somewhat. Those who have what is called mycosis fungoides stage 1A (where less than 10 percent of the skin is involved) and in whom there is stable remission for at least three to five years are insurable at a low substandard range. Cases are reconsidered if the original diagnosis was in error, and indeed one of the more benign causes is identified on a repeat biopsy. Again the small lesion/plaque form of limited extension is prognostically the best variety.
