Congenital leukemia cutis presenting as multiple violaceous lesions in a newborn

We present a case of congenital leukemia cutis that was the presenting sign of systemic acute myeloid leukemia. The initial diagnosis was benign hemangiomatosis because ultrasound of the liver was negative for visceral involvement. However, biopsy showed monocytic cells and led to a further workup which involved a bone marrow biopsy, giving the final diagnosis of acute myeloid leukemia with leukemia cutis. Even with a thorough knowledge of the differential diagnosis of such presenting lesions, a diagnostic biopsy is often needed for a final histologic diagnosis, to proceed with the proper course of treatment. We review congenital leukemia cutis and the differential diagnosis for violaceous lesions in the newborn that may be encountered by the pediatric plastic surgeon.