MF (mycosis fungoides)

Last edited 08/2021 and last reviewed 12/2021

Mycosis fungoides is a non-Hodgkin's lymphoma that arises from CD4+ T lymphocytes (1,2,3,4,5):

• is the most common type of cutaneous T cell lymphoma (5)
• median time to diagnosis is found to be about four years
• may be due to its pleomorphic presentation and often slow disease progression with non-specific eczematous patch lesions for some years (5)

Epidemiology summary (5):

• yearly incidence per 10 million people of 13 in Norway and England/ Wales, 14 in the Netherlands, 15 in Western Australia, and 41 to 64 in the USA
• more often in men than in women with a ratio of 2:1
• ethnicity also affects incidence rates
• black populations have the highest reported incidence rates, followed by white populations
• lowest incidence rates have been reported in Asian and Hispanic populations
• African-American race seems to be associated with a poorer overall survival

The aetiology of mycosis fungoides is unknown, although a variety of risk factors have been proposed, including environmental factors (e.g. occupational exposure, viral infection) and genetic factors (1).

It is a cutaneous lymphoma that characteristically affects middle aged males

• onset of symptoms, generally, occurs in late middle age with a median of 50 to 60 years - however cases in children and adolescents are also known (5)

It usually begins as an eczematous reaction and proceeds to form plaques, tumours and fungating ulcers. Erythroderma may occur which often is highly pruritic

Histologically, MF consists primarily of an epidermotropic dermatitis with an atypical lymphocytic infiltrate, and characteristic Pautrier microabscesses (6)

Treatment options include topical steroids, topical cytotoxic agents, PUVA and radiotherapy

• visceral involvement may require systemic cytotoxic therapy, although responses are often short-lived
  • systemic therapy options include interferon-alpha, oral retinoids, and chemotherapy drugs
• a systematic review concluded (5):
• lack of high-certainty evidence to support decision making in the treatment of MF
• PUVA is commonly recommended as first-line treatment for MF, and we did not find evidence to challenge this recommendation
• absence of evidence to support the use of intralesional IFN-alpha or bexarotene in people receiving PUVA and an absence of evidence to support the use of acitretin or ECP for treating MF

Prognosis relates to extent and type of skin involvement - average survival in the early stage of this disease is at least 10-15 years (2)

Sezary syndrome is the leukaemic presentation of mycosis fungoides (3).

Click here for example images of this condition

Reference:

• (1) Morales Suarez-Varela MM et al (2000). Mycosis fungoides: review of epidemiological observations. Dermatol, 201-21-28.
• (2) Dermatology in practice (2001), 9 (2), 14-18.
• (3) Lorincz AI (1996). Cutaneous T-cell lymphoma (mycosis fungoides). Lancet, 347, 871-876.
• (4) Trautinger F, Knobler R, Willemze R, et al. EORTC consensus recommendations for the treatment of mycosis fungoides/Sezary syndrome. Eur J Cancer. 2006;42(8):1014-1030
• (5)Valipour A et al. Interventions for mycosis fungoides. Cochrane Database of Systematic Reviews 2020, Issue 7. Art. No.: CD008946. DOI: 10.1002/14651858.CD008946.pub3.
• (6) Elston D, Ferringer T, Ko CJ, High WA, DiCaudo DJ. Dermatopathology. Philadelphia: Elsevier; 2014.