Newborn mice were injected with measured doses of EDTA, resulting in the development of a complex of multiple neural crest tumors, hyperplasia, excessive cell proliferation, cell death of neural crest cells and heterotopic melanin pigmentation in the sites where the neural crest cells are present. The occurrence of multiple neural crest tumors as well as the mechanism of EDTA as a teratogen may be associated with cell membrane perturbation. Oncogenesis of neural crest tumors and cell death of neural crest cells from a single agent showed the complexity and variability of phenotypic expression. Neural crest cells may differentiate into many divergent cellular phenotypes derived from an initially undifferentiated stem cell population.