A 59-year-old woman presents to the ED with a complaint of an asthma attack. Incidentally, the patient is noted to have this skin finding.
What is the diagnosis and treatment for this condition?
Diagnosis: Cutaneous T-cell Lymphoma: Mycosis Fungoides
Non-Hodgkin's lymphoma is a relatively rare group of malignant neoplasms involving B cells, T cells, their progenitors, and, rarely, natural killer cells. A total of 4.3 percent of all new cancer cases in the United States are related to non-Hodgkin lymphoma. (Surveillance, Epidemiology, and End Results [SEER] program, National Cancer Institute; http://1.usa.gov/SaJGxa.) Cutaneous T-cell lymphoma (CTCL) represents 3.4 percent of these. CTCL is a diverse group of lymphoproliferative disorders characterized by the clonal expansion of mature T cells that infiltrate the skin. (Hematol Oncol Clin North Am 2008;22:979.)
Mycosis fungoides (MF) is the most common CTCL subtype, representing 44 percent of all primary cutaneous lymphomas. Primary cutaneous CD30+ lymphoproliferative disorders are the second most common subgroup of CTCLs, accounting for nearly 30 percent of these lymphomas. (Blood 2005;105:3768.) Men have an increased incidence of CTCLs compared with women. The incidence of CTCL increases with age, peaking in those aged 70–84. (JAMA Dermatol 2013;149:1295.)
The exact cause of MF is unknown, but it is currently thought to involve chromosomal aberrations. (Cancer Res 2005;65:8101), epigenetic abnormalities, and dysregulation of signaling pathways. (Semin Oncol 2006;33[1 Suppl 3]:S3.) Adhesion molecules and cytokine abnormalities have also been implicated in the pathophysiology of MF. (N Engl J Med 2004;350:1978.)
Patients with MF classically present with persistent, scaly patches in various shades of red and indurated, annular plaques with a central clearing. These lesions may progress to tumors or erythroderma. It should be noted that many clinical variants exist with diverse presentations that may only share diagnostic histological findings. (J Am Acad Dermatol 2002;46:325.) Patients may also experience alopecia, pruritus, and dyspigmentation. (J Am Acad Dermatol 2011;64:53, J Am Acad Dermatol 2011;65:313.) Early diagnosis is challenging because features may overlap with known benign dermatosis, such as Acanthosis nigricans, Erythema multiforme, vitiligo, plaque-type psoriasis, and many more. (J Am Acad Dermatol 2002;47:914.)
Classic early patch-phase MF is characterized by lesions greater than 5 cm in diameter that vary in size, shape, and color. Most patients have multiple lesions that develop on parts of the body not often exposed to the sun, like the trunk, inner arms, thighs, and the bathing suit distribution, although this may vary. The juxtaposition of mottled pigmentation, epidermal atrophy, and telangiectasia (poikiloderma) is also relatively specific for early MF. (J Am Acad Dermatol 2005;53:1053.) Patients present with patches or plaques involving less than 10 percent of the body surface area in 30 percent of MF cases while 37 percent of cases have involvement of more than 10 percent of body surface area. (Arch Dermatol 2003;139:857.)
The differential should include other causes of erythroderma or pruritus, such as generalized atopic dermatitis, psoriasis, drug reactions, and eczema. Also consider Sézary syndrome, the leukemic variant of MF, and other types of cutaneous lymphomas. The diagnosis of early MF involves a scoring system that considers clinical, histopathologic, molecular biological, and immunopathologic findings. The basic clinical criterion is met if a patient experiences persistent or progressive patches or thin plaques. Additional criteria include location in an area not exposed to the sun, variation in size and shape, and poikiloderma. (J Am Acad Dermatol 2005;53:1053.)
Treatment for MF depends on the extent of the disease, with milder cases benefiting from skin-directed therapies like topical corticosteroids (Arch Dermatol 1998;134:949) or phototherapy with narrowband UVB. (J Am Acad Dermatol 2009;60:39.) Combination treatments, systemic therapies, or total skin electron beam therapy may be used if escalating treatment is required. (J Am Acad Dermatol 2002;47:364.)
Patient prognosis varies depending primarily on staging. One cohort study of 1,263 patients with MF or Sézary syndrome found that 11.6 percent progressed to a higher stage and 8.1 percent died from the disease. The median overall survival was 24.4 years, and median progression-free survival was 16 years. Patients with stage IA limited patch and plaque MF did not experience significantly worse overall survival than matched controls. Risk factors for disease progression or death were found to be plaque stage, advanced age at diagnosis, LDH level, and tumor area. (Clin Cancer Res 2012;18:5051.)
This patient was diagnosed with CTCL as an outpatient and started on phototherapy treatments.
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