Mycosis fungoides (MF) (synonyms: cutaneous T-cell lymphoma (CLCL); cutaneous lymphoma; T-cell non-Hodgkin’s lymphoma; Alibert-Bazin syndrome; proliferative lymphoma; ICD-10-GM C84.0: mycosis fungoides) is a chronic T-cell lymphoma (subgroup of non-Hodgkin’s lymphomas) that manifests primarily on the skin (cutaneous lymphoma).
Mycosis fungoides belongs to the primary cutaneous lymphomas and to the group of cutaneous T-cell lymphomas. Approximately 70% of cutaneous T-cell lymphomas exist as primary cutaneous lymphomas.
The initial cell for a T-cell lymphoma is a T-cell that has degenerated, continues to multiply, and affects the skin. Consequently, it is a tumor disease of the T lymphocytes. T cells are part of the immune system.
The disease occurs peripherally (away from the body trunk) and has a low malignancy grade (low malignancy).Because of the eczema formation, the disease was initially thought to be a fungal disease (mycosis), leading to this misleading name.
Sex ratio: Contradictory data on sex distribution exist in the literature.
Frequency peak: The disease occurs predominantly in the second half of life, between the ages of 40 and 70 (mean age of onset 55-60 years).
Mycosis fungoides, although the most common malignant cutaneous lymphoma (2%), is in itself a very rare disease. The incidence (frequency of new cases) is 0.3-0.5 cases per 100,000 population per year.
Course and prognosis: Mycosis fungoides progresses in stages. In the first stage, the disease develops very slowly and initially presents as chronic, pruritic exanthema (rash). It begins focally (focal). A cure is still possible in the first stage. As the disease progresses, the degree of skin involvement increases. New foci appear repeatedly, while old foci progress in their expression and severity (polymorphic picture). In the advanced stage (tumor stage), the disease progresses rapidly and affects the nearby lymph nodes as well as internal organs (spleen, liver, lungs, CNS). The prognosis is then poor. However, therapeutic measures can still achieve longer-lasting remissions (permanent abatement of disease symptoms, but without achieving recovery) even then.
The average life expectancy after diagnosis is 7-10 years. The prognostic factor is the stage at diagnosis.
