LY15 Twenty-nail dystrophy as the initial presentation of mycosis fungoides

Abstract

Nail involvement in mycosis fungoides (MF) is uncommon and rarely represents the initial manifestation. A 60-year-old man with no significant past medical history presented with 20-nail dystrophy of 1-year duration. This was associated with intensely pruritic hyperkeratotic lesions with fissuring on the palmoplantar surfaces, although the proximal nailfolds were relatively unaffected. Disease progression occurred with development of eczematous patches on the trunk, followed by the face and limbs, significantly impairing his quality of life. Skin biopsy demonstrated epidermotropic cutaneous T-cell lymphoma consistent with MF, with CD30 positivity, staged as stage IB disease. He was commenced on oral methotrexate (10 mg weekly). Despite treatment, he developed rapidly progressive bulky cervical and inguinal lymphadenopathy within 3 months. Core biopsy of an inguinal lymph node confirmed CD30-positive T-cell lymphoma with large cell transformation. Systemic therapy with brentuximab vedotin was initiated, resulting in marked clinical improvement of his skin and nails and significant reduction in lymphadenopathy after two cycles. The most common nail changes described in patients with MF include longitudinal ridging, nail thickening, nail fragility and leuconychia (Ehsani AH, Nasimi M, Azizpour A et al. Nail changes in early mycosis fungoides. Skin Appendage Disord 2017; 4: 55–9). Twenty-nail dystrophy as the presenting feature of MF, preceding classical cutaneous features, is rare and may contribute to diagnostic delay. Large cell transformation is typically associated with advanced MF (Diamandidou E, Colome-Grimmer M, Fayad L et al. Transformation of mycosis fungoides/Sézary syndrome: clinical characteristics and prognosis. Blood 1998; 92: 1150–9). However, this case highlights that aggressive transformation can occur early in the disease course and may be refractory to skin-directed and low-dose systemic therapies.