Classic mycosis fungoides

Classic mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma (CTCL), a group of non-Hodgkin lymphomas that primarily affect the skin. In this condition, malignant T-lymphocytes (a type of white blood cell) accumulate in the skin, causing characteristic lesions that typically progress through three clinical stages: patches, plaques, and tumors. The disease predominantly affects the skin but can, in advanced stages, spread to lymph nodes, blood, and internal organs. Classic mycosis fungoides is also known as Alibert-Bazin type mycosis fungoides. The disease typically presents in middle-aged to older adults and follows an indolent (slow-growing) course over years to decades. Early-stage disease manifests as flat, scaly, erythematous (reddish) patches, often in sun-protected areas such as the buttocks, trunk, and proximal extremities. These patches may be mistaken for eczema, psoriasis, or other benign dermatoses, frequently leading to diagnostic delays. As the disease progresses, patches may evolve into thickened, raised plaques and eventually into tumors that can ulcerate. Patients often experience significant pruritus (itching), which can substantially impair quality of life. A minority of patients progress to erythroderma (widespread skin redness) or develop extracutaneous involvement. Treatment depends on the stage of disease. Early-stage mycosis fungoides is managed with skin-directed therapies including topical corticosteroids, topical nitrogen mustard (mechlorethamine), phototherapy (narrowband UVB or PUVA), and localized radiation therapy. For more advanced or refractory disease, systemic therapies may be employed, including retinoids (bexarotene), interferon-alpha, histone deacetylase inhibitors (vorinostat, romidepsin), monoclonal antibodies (mogamulizumab, brentuximab vedotin), and extracorporeal photopheresis. Allogeneic stem cell transplantation may be considered in select younger patients with aggressive disease. Early-stage classic mycosis fungoides generally carries a favorable prognosis with near-normal life expectancy, while advanced-stage disease is associated with significantly reduced survival.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

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