‘Leukaemic pernio’: perniosis-like presentations of chronic lymphocytic leukaemia

Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in adults. Skin involvement by malignant CLL cells, or leukemia cutis (LC), typically presents as localized or generalized papulonodular lesions. Here we report a series of five patients with CLL who presented with perniosis-like skin findings on the ears, nose, and/or digits. Histopathologic analysis of seven skin specimens from these five patients showed a relatively dense, nodular to diffuse, pan-dermal infiltrate of monomorphic lymphocytes, compatible with CLL. The typical histopathologic findings of perniosis, such as a robust perivascular and peri-eccrine infiltrate, dermal edema, and interface change, were absent. In one patient, the skin findings heralded the diagnosis of CLL, and in most patients the skin lesions tended to improve with systemic treatment of the patient's underlying CLL. We suggest the term 'leukemic pernio' for cases of leukemia cutis that clinically mimic perniosis.