Blueberry muffin baby, also known as extramedullary hematopoiesis, describes a newborn baby with multiple purpura, associated with several non-cancerous and cancerous conditions in which extra blood is produced in the skin. The bumps range from 1-7mm, do not blanche and have a tendency to occur on the head, neck and trunk. They often fade by 3 to 6 weeks after birth, leaving brownish marks. When due to a cancer, the bumps tend to be fewer, firmer and larger.