Image Gallery: Hairy‐cell leukaemia presenting with Sweet syndrome

Dear Editor, A 57-year-old man presented with a 1-month history of fevers, dermatitis and pancytopenia in the setting of a 14-lb weight loss, fatigue, night sweats and arthralgia. Skin examination revealed multiple erythematous papules on the (a) trunk and (b) extremities. Erythrocyte sedimentation rate and C-reactive protein were elevated (104 mm h−1 and 14·8 mg L−1, respectively). Work-up was negative for infection or autoimmune conditions. (c, d) Skin biopsy was notable for dense neutrophilia and dermal oedema, consistent with Sweet syndrome. Bone marrow biopsy and flow cytometry were consistent with hairy-cell leukaemia, which constitutes only 2% of all leukaemias.1 Treatment with cladribine and prednisone resulted in improved cell counts and resolution of the rarely observed hairy-cell leukaemia-associated Sweet syndrome.1, 2