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 is common, perhaps in 20 percent of patients, but is not universal. The symptoms displayed are progressive, with early stages consisting of lesions presented as scaly patches. These lesions prefer the buttock region. The later stages involve the patches evolving into plaques distributed over the entire body. The advanced stage of mycosis fungoides is characterized by generalized erythroderma, with severe pruritus and scaling.
Cause
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, although some research suggests that the Human T-lymphotropic virus is associated with this condition. The disease is an unusual expression of CD4 T cells, a part of the immune system. These T cells are skin-associated, meaning they are biochemically and biologically most related to the skin, in a dynamic manner. Mycosis fungoides is the most common type of cutaneous T-cell lymphoma, but there are many other types of CTCL that have nothing to do with mycosis fungoides and these disorders are treated differently.
Diagnosis
Diagnosis is sometimes difficult because the early phases of the disease often resemble eczema or even psoriasis. Several biopsies are recommended, to be more certain of the diagnosis. The criteria for the disease are established on the skin biopsy:
the superficial papillary dermis is infiltrated by a bandlike lymphocyte infiltrate
epidermotropism
presence of atypical T-cells with cerebriform nuclei in the dermal and epidermal infiltrates.
Pautrier's microabcesses are aggregates of four or more atypical lymphocytes arranged in the epidermis. Pautrier microabcesses are characteristic of mycosis fungoides but are generally absent. 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 and plaques. Peripheral smear will often show buttock cells.
Staging
Traditionally, mycosis fungoides has been divided into three stages: premycotic, mycotic and tumorous. The premycotic stage clinically presents as an erythematous, 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 the tumorous stage a dense infiltrate of medium-sized lymphocytes with cerebriform nuclei expands the dermis.
Prognosis
A 1999 US-based study of patient records observed a 5-year relative survival rate of 77%, and a 10-year relative survival rate of 69%. After 11 years, the observed relative survival rate remained around 66%. Poorer survival is correlated with advanced age and black race. Superior survival was observed for married women compared with other gender and marital-status groups.
It is rare for the disease to appear before age 20, and it appears to be noticeably more common in males than females, especially over the age of 50, where the incidence of the disease does increase. The average age of onset is between 45 and 55 years of age for patients with patch and plaque disease only, but is over 60 for patients who present with tumours, erythroderma or a leukemic form. The incidence of mycosis fungoides was seen to be increasing till the year 2000 in the United States, thought to be due to improvements in diagnostics. However, the reported incidence of the disease has since then remained constant, suggesting another unknown reason for the jump seen before 2000.
History
Mycosis fungoides was first described in 1806 by French dermatologist Jean-Louis-Marc Alibert. The name mycosis fungoides is very misleading—it loosely means "mushroom-like fungal disease". The disease, however, is not a fungal infection but rather a type of non-Hodgkin's lymphoma. It was so named because Alibert described the skin tumors of a severe case as having a mushroom-like appearance.
Famous cases
In 1995 actor Mr. T was diagnosed with a cutaneous T-cell lymphoma, or mycosis fungoides. Once in remission, he joked about the coincidence: "Can you imagine that? Cancer with my name on it — personalized cancer!"
