Diagnosis: CD30+ transformed mycosis fungoides
Repeat biopsies ultimately confirmed a diagnosis of mycosis fungoides (MF), a primary cutaneous non-Hodgkin lymphoma of T-cell origin.
Lymphomas occurring in the skin without evidence of disease in other areas of the body at the time of diagnosis are referred to as primary cutaneous lymphomas. They are broadly divided by their cell of origin into cutaneous T-cell and cutaneous B-cell lymphomas. Differentiating primary cutaneous lymphoma from systemic lymphomas with secondary skin involvement is an important distinction, as primary cutaneous lymphomas have different clinical courses and prognoses and require different treatments.1
MF is the most common type of cutaneous T-cell lymphoma (CTCL), yet it remains an uncommon diagnosis as cutaneous lymphomas comprise only 3.9% of all non-Hodgkin lymphomas.2 The CD30+ transformed variant identified in this patient is a rare subtype of MF that is associated with increased morbidity and mortality.3 Other types of CTCL include primary cutaneous anaplastic large cell lymphoma, lymphomatoid papulosis, and adult T-cell leukemia/lymphoma, all of which can resemble MF clinically and are diagnosed by histopathology.
A nonspecific presentation
Patients with MF typically present with a complaint of chronic, slowly progressive skin lesions of various sizes and morphologies including scaly patches, plaques, and tumors, often in skin distributions that are not directly exposed to the sun (often referred to as a “bathing suit” distribution).4 Pruritus typically accompanies these skin lesions, and alopecia and poikiloderma are common findings. Patients with more advanced cases may present with generalized erythroderma. This finding should raise concern for progression to Sézary syndrome, a more aggressive type of CTCL that manifests with leukemic involvement of malignant T-cells matching the T-cell clones found in the skin.2
Alopecia is a common manifestation of MF that can be clinically indistinguishable from alopecia areata.5 While isolated alopecia is unlikely to be a consequence of MF, alopecia in the setting of widespread patches and plaques should raise suspicion for a diagnosis of MF.
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