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PNET is no longer an accepted classification for CNS tumors and has been folded into Embryonal Tumors with Multilayered Rosettes. This change was made in 2016 |
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The rate of PNETs in not correlated with sex, but it shows a correlation with age.<ref name=":0" /> Most cases occur in children around 5 years of age, having a very low frequency in adults.<ref name=":0" /> Regarding genetic mutations, a specific type of gene alteration that directly leads to this tumor hasn't been defined yet.<ref name=":0" /> However, a positive correlation between individuals with [[Li–Fraumeni syndrome|Li-Fraumeni syndrome]] with a mutation in the [[P53|gene ''p53'']] and PNET has been reported.<ref name=":1" /> A significant number of individuals with mutations on the [[Retinoblastoma protein|''rb'' tumor suppressor gene]] have also developed the tumor.<ref name=":1" /> Such gene encodes for the protein Rb responsible for stopping the cell cycle at the [[G1 phase]].<ref name=":4">{{Cite journal|last=Baker|first=Henry V|date=June 2003|title=Essential Genetics: A Genomics Perspective. Third Edition. By Daniel L Hartl and , Elizabeth W Jones. Sudbury (Massachusetts): Jones and Bartlett Publishers. $78.95 (paper). xxvi + 613 p; ill.; index. 2002.|isbn=0-7637-1852-1|journal=The Quarterly Review of Biology|volume=78|issue=2|pages=[https://archive.org/details/essentialgenetic0000hart/page/225 225–226]|doi=10.1086/377959|issn=0033-5770|url-access=registration|url=https://archive.org/details/essentialgenetic0000hart/page/225}}</ref> Another possible contributing factor are mutations in the [[CREB-binding protein]], whose function includes activating transcription,<ref name=":4" /> but this interaction still need to be studied further.<ref name=":1" /> It has also been presumed that the tumor can arise from cranial irradiation.<ref name=":1" />
== Diagnosis ==–
[[File:MRI of PNET.jpg|thumb|[[Magnetic resonance imaging|Magnetic resonance]] image of PNET]]
Most children that develop primitive neuroectodermal tumors are diagnosed early in life, usually at around 3-6.8 years of age.<ref name=":1" /> Symptoms patients present at time of diagnosis include irritable mood, visual difficulties, [[lethargy]], and [[ataxia]].<ref name=":1" /> The circumference of the patient's head might also suffer an enlargement and they might be subject to seizures, especially if they have less than one year of life.<ref name=":1" />
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