Neuroblastoma is a malignant tumor of neural crest cells, the cells that give rise to the sympathetic nervous system, which is observed in children.

Petechiae are pinpoint-sized reddish/purple spots, resembling a rash, that appear just under the skin or a mucous membrane when capillaries have ruptured and some superficial bleeding into the skin has happened. This term refers to an abnormally increased susceptibility to developing petechiae.