Mycosis fungoides, also known as Alibert-Bazin syndrome or granuloma fungoides, is the most common form of cutaneous T-cell lymphoma. It generally affects the skin, but may progress internally over time. Symptoms include rash, tumors, skin lesions, and itchy skin.
While the cause remains unclear, most cases are not hereditary. Most cases are in people over 20 years of age, and it is more common in men than women. Treatment options include sunlight exposure, ultraviolet light, topical corticosteroids, chemotherapy, and radiotherapy.
Signs and symptoms
Typical visible symptoms include rash-like patches, tumors, or lesions. Itching (pruritus) is common, perhaps in 20 percent of patients, and is not universal.
The cause of mycosis fungoides is unknown, but it is not believed to be hereditary or genetic in the vast majority of cases. One incident has been reported of a possible genetic link. It is not contagious.
The disease is an unusual expression of CD4 T cells, a part of the immune system. These T cells are skin-associated, meaning that they biochemically and biologically are most related to the skin, in a dynamic manner. Mycosis fungoides is the most common type of cutaneous T-cell lymphoma (CTCL), but there are many other types of CTCL that have nothing to do with mycosis fungoides and these disorders are treated differently.
Diagnosis is sometimes difficult because the early phases of the disease often resemble eczema or even psoriasis. As with any serious disease, it is advisable to pursue the opinion of a medical professional if a case is suspected. Diagnosis is generally accomplished through a skin biopsy. Several biopsies are recommended, to be more certain of the diagnosis. The diagnosis is made through a combination of the clinical picture and examination, and is confirmed by biopsy.
To stage the disease, various tests may be ordered, to assess nodes, blood and internal organs, but most patients present with disease apparently confined to the skin, as patches (flat spots) and plaques (slightly raised or ‘wrinkled’ spots).
Traditionally, mycosis fungoides has been divided into three stages: premycotic, mycotic and tumorous. The premycotic stage clinically presents as an erythematous (red), itchy, scaly lesion. Microscopic appearance is non-diagnostic and represented by chronic nonspecific dermatosis associated with psoriasiform changes in epidermis.
In the mycotic stage, infiltrative plaques appear and biopsy shows a polymorphous inflammatory infiltrate in the dermis that contains small numbers of frankly atypical lymphoid cells. These cells may line up individually along the epidermal basal layer. The latter finding if unaccompanied by spongiosis is highly suggestive of mycosis fungoides. In tumorous stage, dense infiltrate of medium sized lymphocytes with cerebroid nuclei, expands the dermis.
Mycosis fungoides can be treated in a variety of ways.
If treatment is successful the disease can go into a non-progressing state with clinically clear examination and various tests. This is called remission; it can last indefinitely. Treatments may also cause disease not to progress, while still present, and this is called stable disease; it may last indefinitely but is a more serious situation. Disease may also progress, to involve nodes, blood and internal organs, or transform into a higher-grade lymphoma.
Common treatments include simple sunlight, ultraviolet light, topical steroids, topical and systemic chemotherapies, local superficial radiotherapy, the histone deacetylase inhibitor vorinostat, total skin electron beam radiation, photopheresis and systemic therapies (e.g. interferons, retinoids, rexinoids) or biological therapies. Treatments are often used in combination.
Selection of treatments typically depends on patient preference and access to therapies, as well as recommendations by physicians, the stage of the disease, established resistance to prior therapies, allergies of the patient, clinical evidence of a positive benefit:risk ratio, and so on.
It is incurable, but many patients experience prolonged periods of disease-control. Quality of life is a major objective, in addition to cure, and maximizing periods of remission or stable disease, while minimizing treatments and toxicities, are two central concerns in clinical care.
In 2010, the U.S. Food and Drug Administration granted orphan drug designation for naloxone lotion, a topical opioid receptor competitive antagonist used as a treatment for pruritus in cutaneous T-cell lymphoma.