Chilblain-Like Eruption Unveiling Cutaneous Aleukemic Relapse of Acute Myeloid Leukemia.

Leukemia cutis corresponds to skin infiltration by malignant hematopoietic cells. It is most commonly reported in acute myeloid leukemia, particularly in subtypes with a monocytic component. Its clinical manifestations are extremely variable, and histopathologic diagnosis of cutaneous leukemic infiltrates may be challenging. We report the first case of cutaneous, that is, extramedullary, aleukemic relapse of acute myeloid leukemia within an unusual chilblain-like eruption that imposed a challenging clinical and histopathologic diagnosis. Primary chilblains are uncommon in the elderly, and a systemic underlying cause should be thoroughly investigated. In patients presenting with atypical chilblains (ie, persistent chilblains developing even without exposure to cold temperatures and/or refractory to therapy) and with a history of hematologic disorders such as leukemias, histopathologic examination is crucial to identify leukemic or aleukemic phases of relapse of underlying leukemia and initiate timely treatment.