Chilblain-like leukemia cutis.

We present a 6-year-old girl with an 8-month history of fluctuating chilblain-like lesions on the toes. A full blood count showed slight thrombocytopenia and monocytosis. A skin biopsy specimen showed a dense perivascular and superficial dermal cellular infiltrate which was CD3(-), CD43(+), and lysosyme + on immunocytochemistry, suggesting a monocytic origin. Juvenile myelomonocytic leukemia was diagnosed after a bone marrow biopsy and spontaneous marrow colony growth in culture.