Livedo reticularis.

Livedo reticularis (LR) is a net-like, violaceous, hyperpigmented pattern on the skin that reflects an underlying change in cutaneous blood flow. The causes of LR are many and most commonly include connective tissue diseases, vasculitis, hypercoagulability, and embolic events. We describe a 49-year-old man who presented with painful LR and ulcers on the lower extremities as a manifestation of chronic natural killer cell leukemia (CNKL). There have been only a few cases previously reported in the literature. We report an additional case of a patient with both LR and CNKL and suggest a possible mechanism that explains this association.