Mycosis Fungoides: a review

Abstract

Mycosis fungoides (MF) is the commonest subtype of cutaneous lymphoma, characterised by the infiltration of malignant T cell clones into the skin. It accounts for approximately 60% of all cutaneous T-cell lymphoma (CTCL) diagnoses. MF has three distinct stages - patch, plaque and tumour - presenting most commonly on the buttocks, trunk and breast. The presentation often mimics common inflammatory dermatoses such as eczema and psoriasis. Despite numerous theories, the aetiology of MF remains mostly unknown. Since its first description in 1806, diagnosis has remained a challenge and requires careful clinicopathological correlation. Patients may require multiple skin biopsies, especially in patch stage, to identify the characteristic epidermotropic infiltrates of small to medium-sized lymphocytes. First-line management involves skin-directed therapies (SDT) such as topical corticosteroids, and phototherapy. If this is unsuccessful, systemic medications such as interferon alpha, oral bexarotene, methotrexate and novel antibody therapies are trialled. MF can also respond to localised radiotherapy, total skin electron beam therapy and haematopoietic stem cell transplant. Despite being primarily a cutaneous lymphoma, MF can progress to involve other organs. This review provides a comprehensive overview of the epidemiology, clinical features, diagnosis and management of mycosis fungoides.