Mycosis fungoides

Mycosis fungoides (MF) is a T- cell non -Hodgkin's lymphoma that primarily affects the skin. As first described by the French physicians Jean -Louis -Marc Alibert and Pierre -Antoine -Ernest Bazin apply in the first half of the 19th century. The disease is therefore also referred to as Alibert - Bazin syndrome. This name is - just like the older German name Wucherflechte - but hardly in use.

Because of the skin manifestations believed the describer to have to deal with a fungal disease ( mycosis ) of the skin, hence the misleading name. So far, however, there is no sure evidence that the disease is caused by infectious agents (viruses, bacteria, fungi).

The disease is accompanied by vicious degenerate (CD4 positive ) T -helper cells. Overall, this is a very rare disease ( only 0.5 % of all malignant lymphomas), among the primary cutaneous T -cell lymphomas, however, the MF is the most common form.

Patients

Mycosis fungoides primarily affects patients over 40 years (median 50-60 a).

The disease also occurs in animals. Dogs with atopic dermatitis have a 12 - fold increased risk of the disease.

Stages and symptoms

  • Prämykotisches stage:

The prämykotische stage is characterized by uncharacteristic rash with intractable pruritus and desquamation may esp. of the trunk. The lesions can disappear and reappear at another location. This eczema -like lesions may persist for years at this stage and then become the infiltrative plaque stage. In prämykotischen stage cures are still possible in some cases.

  • Plaque stage:

At this stage there are often annular, plaque -like and slightly raised lesions, which may vary in severity.

  • Tumor stage

At this stage results in the formation of multiple, nodular and red -brown tumor nodules in the skin, often around the face ( leonine facies, lion face ). The nodes may ulcerate. In severe cases there is erythroderma. At this stage it usually comes for systemic spread of Lymphomes.

  • Lymph node involvement:

At this stage it comes to attack by multiple nodes.

  • Involvement of the internal organs:

The mycosis fungoides attacks in the advanced stage liver, spleen, lungs and blood. The bone marrow is affected in approximately 30% of patients. The involvement of the internal organs is prognostically unfavorable.

Tumor staging

The tumor staging is done according to the rules of the TNM system. In addition, the staging by the AJCC ( American Joint Cancer Committee) is used clinically.

Pathology

Histologically fall into the affected skin areas polymorphonuclear infiltrates mainly in the dermis prove. With disease progression predominate in these infiltrates more and more the actual neoplastic cells. These are mostly small, have a zerebriform lobed nucleus and comply with their immunophenotype of T -helper cells. They show a clear epidermotropism, that is, they infiltrate the dermis produces the epidermis. In the higher layers of the epidermis (especially the stratum spinosum ), they form the so-called Pautrier - microabscesses, ie small focal tumor cell islands. The affected skin is also usually a para-and ortho- keratosis and irregular acanthosis. In the outflow area of the skin lesions lymph nodes can show the image of a so-called dermatopathischen lymphadenitis. In such altered lymph nodes lymphoma can not always be diagnosed with certainty.

Could be recently detected with sensitive methods in bone marrow and in the lymph node tumor cells also in the localized to the skin stadiums. The clinical significance of this fact is not yet entirely clear. In the plaque and tumor stage can be up to 25 % of the patient's tumor cells detected in the blood smear.

There are no known characteristic chromosomal changes. The molecular basis of epidermotropism is not yet clear. Presumably expressing tumor cells specific homing factors and are dependent on skin - specific growth factors. Also normal T lymphocytes show a part epidermotropism.

Etiology

The etiology of the disease is unclear. However, there are different notes:

  • Viral hypothesis: There are other T-cell - lymphoma, which are associated with the virus HTLV -1. This did not show up in mycosis fungoides.
  • In part one finds increasingly allergic reaction type IV, suggesting an increased activity of T helper cells in patients.
  • In many patients there was an increased exposure to chemicals. People who are active in the metal processing or agriculture, have an increased risk.
  • Chronic inflammation should lead to the chronic stimulation and proliferation of T lymphocytes.

Diagnostics

The diagnosis is usually done by a biopsy from the affected areas of the skin or tumorous lesions in the generalized stages also in biopsies from lymph nodes, bone marrow and the affected organs. In the bone marrow infiltrates may be similar to a B -CLL, but the infiltrates are in contrast to B -CLL acid phosphatase and acid naphthol Acetatesterase -positive. The leukemic Sezary syndrome can be diagnosed on blood smear and immunophenotypic typing. The monoclonality of the tumor cells can be detected by molecular biology of T- cell receptor rearrangements.

Special shapes

See also: Sezary Syndrome

The Sezary syndrome is a generalized erythrodermic and leukemic variant of mycosis fungoides with poor prognosis. In contrast to mycosis fungoides, the disease will usually not in the stage of cancer continues, but the tumor cells (so-called Sézary or Lutzner cells ) propagate generalized early via the blood and infect the bone marrow, lymph nodes and other organs. Sezary cells have the phenotype of the mature T- lymphocytes ( CD4 positive CD5 positive) and are characterized by their typical cerebriform cell nucleus. These cells are found fungoides in the tissue infiltrates of mycosis. Therapeutic Sézary syndrome as mycosis fungoides treated.

Differential Diagnosis

In prämykotischen stage mycosis fungoides is to be distinguished mainly by primary, eczema (eg atopic eczema, psoriasis )

Therapy

Stages accessible

Stage 1:

  • Excision in healthy
  • Photochemotherapy with psoralen and UV treatment ( PUVA)

Stage 2:

  • Photochemotherapy with psoralen and UV treatment ( PUVA)
  • Topical treatment with retinoids, corticosteroids, among others
  • Local cytostatics
  • Radiotherapy and total body irradiation

Stage 3:

  • Photochemotherapy with psoralen and UV treatment ( PUVA)
  • Interferon- alpha therapy
  • Monoclonal antibody therapy (such as anti- CD52, Campath ®)
  • Combination chemotherapy
  • In special centers extracorporeal photopheresis

General measures:

  • Treatment of itching (pruritus )

Forecast

In Stage I, the disease suspend for years or are cured. Otherwise, mycosis fungoides is considered incurable disease. The Sezary syndrome has a poor prognosis. Also, a disorder characterized by tumor cells with the immunophenotype of T- suppressor cells ( CD8 positive) seems prognostically unfavorable.

Complications

  • Transition to a highly malignant T -cell lymphoma ( large cell T -cell lymphoma )
  • Involvement of the internal organs
  • Functional immunosuppression (probably due to secreted by the lymphoma factors )
Cutaneous lymphoma Papule TNM staging system Epidermis (skin) Parakeratosis Lymphadenopathy Blood film PUVA therapy
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