<prompt> Cells from the neural crest are involved in all except.Hirschsprungs diseaseNeuroblastomaPrimitive neuroectodermal tumourWilms tumour  <response>: Ans. is d i.e. Wilms Tumour Lets first see: -Neural crest derivatives: -Schwann cellsNeurons of sympathetic gangliaNeurons of spinal posterior nerve root ganglia or Dorsal root ganglia Specific cells of adrenal medullaNeurons of sensory ganglion of 5th, 6th, 7th, 8th and 10th cranial nervesChromaffin tissueMelanoblast of skinPia and arachnoid materDentine toothNow lets see neural crest is involved in which of the following diseasesHirschsprungs disease-The major histopathological feature of Hirschsprungs disease is absence of ganglion cells in the neural plexus. It is believed to result from the failure of migration of neuroblast into the gut from vagal nerve. The sensory ganglions of vagus nerve are derived from neural crest. See point 5 so we can say that neural crest in involved.NeuroblastomaNo doubts above it. It is a malignant tumour of neural crest origin See point 4Primitive neuroectodermal tumours -PETs include medulloblastoma, neuroblastoma, Pineoblastoma and ependyma-blastomas.Here is a definition of primitive neuroectodermal tumours from Borlands medical dictionary It is a proposed name for a heterogeneous group of neoplasms thought to be derived from undifferentiated neuroglial cells of the neural crest Some occur in brain and some occur in sites such as extremities pelvis or the chest wall.Wilms tumourIt is a mixed tumour consisting of epithelial and connective tissue elements. It is derived from neuroblast. No relation to neural crest. 