Transient blueberry muffin appearance of a newborn with congenital monoblastic leukemia.

A full-term male infant was born with skin findings suggesting a blueberry muffin appearance. Biopsy of a cutaneous nodule was consistent with monoblastic leukemia cutis, and bone marrow examination confirmed the diagnosis of leukemia. The infant has remained well 2 years after spontaneous resolution of the cutaneous eruption. Infiltrative neoplasms should be considered along with congenital infections and hematologic disorders in the differential diagnosis of a newborn with a blueberry muffin appearance.