Primitive neuroectodermal tumor: Difference between revisions

Revision as of 01:45, 3 October 2014

Latest revision as of 16:41, 22 September 2024

(46 intermediate revisions by 24 users not shown)

Line 1:

{{Short description|Cancer of the developing nervous system}}

{{Infobox_Disease |

{{hatnote|Not to be confused with [[pancreatic neuroendocrine tumor]], which is also abbreviated as PNET.}}

Name = Primitive neuroectodermal tumor |

{{Infobox medical condition (new)

Image = PNET_Histopathology_HE_200x.jpg |

| name Name = Primitive neuroectodermal tumor |

Caption = Micrograph of an H&E stained section of a peripheral PNET. |

| image Image = PNET_Histopathology_HE_200x.jpg |

DiseasesDB = 31470 |

| caption Caption = Micrograph of an H&E stained section of a peripheral PNET. |

ICD10 = |

|

ICD9 = |

| ICDO pronounce = {{ICDO|9473|3}} |

| OMIMfield = | Oncology

| synonyms MedlinePlus = | PNET

| symptoms =

eMedicineSubj = ped |

| complications =

eMedicineTopic = 2589 |

| onset =

eMedicine_mult = {{eMedicine2|neuro|326}} |

| MeshID duration = D018242 |

| types =

| causes =

| risks =

| diagnosis =

| differential =

| prevention =

| treatment =

| medication =

| prognosis =

| frequency =

| deaths =

}}

'''Primitive Neuroectodermalneuroectodermal Tumortumor''' (PNET) is a malignant (cancerous) [[neural crest]] tumor.<ref>{{DorlandsDict|eight/000112249|primitive neuroectodermal tumor}}</ref> It is a rare [[tumor]], usually occurring in children and young adults under 25 years of age. The overall 5 year survival rate is about 53%.<ref name=Smoll20111>{{citeCite journal doi| last1 = Smoll | first1 = N. R. | title = Relative survival of childhood and adult medulloblastomas and primitive neuroectodermal tumors (PNETs) | doi = 10.1002/cncr.26387 | journal = Cancer | volume = 118 | issue = 5 | pages = 1313–1322 | year = 2012 | pmid = 21837678| s2cid = 8490276 | doi-access = free }}</ref>

It gets its name because the majority of the cells in the tumor are derived from [[neuroectoderm]], but have not developed and differentiated in the way a normal [[neuron]] would, and so the cells appear "primitive". PNET belongs to the [[Ewing family of tumors]].

==Genetics==

PNET belongs to the [[Ewing family of tumors]].

Using gene transfer of SV40 large T-antigen in neuronal precursor cells of rats, a brain tumor model was established. The PNETs were histologically indistinguishable from the human counterparts and have been used to identify new genes involved in human brain tumor carcinogenesis.<ref name="pmid8129041">{{cite journal |authorvauthors=Eibl RH, Kleihues P, Jat PS, Wiestler OD |title=A model for primitive neuroectodermal tumors in transgenic neural transplants harboring the SV40 large T antigen |journal=Am. J. Pathol. |volume=144 |issue=3 |pages=556–64 |date=March 1994 |pmid=8129041 |pmc=1887088 |doi= |url=}}</ref> The model was used to confirm p53 as one of the genes involved in human medulloblastomas, but since only about 10% of the human tumors showed mutations in that gene, the model can be used to identify the other binding partners of SV40 Large T- antigen, other than p53.<ref name="pmid1933879">{{cite journal |authorvauthors=Ohgaki H, Eibl RH, Wiestler OD, Yasargil MG, Newcomb EW, Kleihues P |title=p53 mutations in nonastrocytic human brain tumors |journal=Cancer Res. |volume=51 |issue=22 |pages=6202–5 |date=November 1991 |pmid=1933879 |doi= |url=http://cancerres.aacrjournals.org/cgi/pmidlookup?view=long&pmid=1933879}}</ref>{{additional citation needed|date=July 2021}}

==Classification==

It is classified into two types, based on ___location in the body: peripheral PNET and CNS PNET.

==Diagnosis==

===Peripheral PNET===

[[File:Peripheral PNET CD99 200x.jpg|thumb|CD99 staining of tissue from peripheral PNET]]

===Classification===

It is classified into two types, based on ___location in the body: peripheral PNET and CNS PNET.{{citation needed|date=June 2020}}

====Peripheral PNET====

The peripheral PNET (pPNET) is now thought to be virtually identical to [[Ewing's sarcoma|Ewing sarcoma]]:

"Current evidence indicates that both Ewing's sarcoma and PNET have a similar neural phenotype and, because they share an identical chromosome translocation, they should be viewed as the same tumor, differing only in their degree of neural differentiation. Tumors that demonstrate neural differentiation by light microscopy, immunohistochemistry, or electron microscopy have been traditionally labeled PNETs, and those that are undifferentiated by these analyses have been diagnosed as Ewing's sarcoma."<ref name="robbins">Kumar, Vinay; Fausto, Nelso; Abbas, Abul (2004) ''Robbins & Cotran Pathologic Basis of Disease'' (7th ed.). Saunders. Page 1301. {{ISBN |0-7216-0187-1}}.</ref>

====PNET of the CNS====

[[File:PNET.jpg|thumb|Supratentorial central PNET in a 5-year-old patient]]

{{main|Central nervous system primitive neuroectodermal tumor}}

PNET of the CNS generally refer to supratentorial PNETs.

* In the past [[medulloblastoma]]s were considered PNETs; however, they are genetically, transcriptionally and clinically distinct. As such, "infratentorial" PNETs are now referred to as medulloblastoma {{Citation needed|date=March 2013}}.

* In the past [[medulloblastoma]]s were considered PNETs; however, they are genetically, transcriptionally and clinically distinct. As such, "infratentorial" PNETs are now referred to as medulloblastoma {{Citation needed|date=March 2013}}.

* [[Pineoblastoma]]s are embryonal tumours originating in the [[pineal gland]] and are likely distinct from supratentorial PNETs.

==SurvivalTreatment==

Patients diagnosed with a medulloblastoma or PNET are 50 times more likely to die than a matched member of the general population. The 5-year relative survival estimates (based on data from 2001–2006) are 64% in children (1–9 years), 35% in adults (20–25 years), and two known survivors over the age of 25 (Brian Fitzpatrick) aged 34 in 2002. In 2007 a PNET was discovered in the oldest known patient(Tim Young 41 years of age) in Atlanta wrapped around the spinal cord in the C4 cervical area for the first time. A sample was removed by Neurosurgeon Dr David Disch, and the spinal cord was compromised to avoid the tumor from entering the spinal fluids. The procedure caused right side hemiparesis but no other effects. Oncologist Dr Ron Steis(Atlanta Cancer Care) and a global team administered 15 rounds of 5 types of chemo, followed up by 8 weeks of trilogy radiation, and 22 additional rounds of chemo until the patient was cleared. As of March 2014 Mr Young is still the oldest known survivor of PNET.

The approach to management of a CNS PNET is first to obtain detailed imaging through MRI, as well as additional scans of the patient's body (X-ray, CT, PET, even bone marrow biopsies) to look for metastasis or other associated malignancies. The tumor will then need to be biopsied to confirm the diagnosis. After the diagnosis of a CNS PNET is confirmed, management includes neoadjuvant chemotherapy and radiation (to reduce tumor size burden), complete surgical resection with confirmed negative margins, and/or additional adjuvant post-surgical chemotherapy. CNS PNET is aggressive and must be managed as so. Palliative care services should also become involved in the patient's care team when the diagnosis is made.

Oncologists, Dr. Thomas Leavitt and Dr. Lyn Soe (Cameron Park Oncology, Cameron Park CA) treated Tamara H. Ruiz for PNET. Following major surgery and official diagnosis in April 1997, a rigorous protocol which included 5 types of chemo, radiation as well as additional rounds of chemo was initiated. The patient was 47 years of age at the time of diagnosis. As of September 2014 Tamara H. Ruiz currently age 65, is currently free of disease and appears to be the oldest known survivor of PNET.

<ref>Honrado, Carlo P, and Augustine L Moscatello. Primitive Neuroectodermal Tumors: Background, Epidemiology, Clinical Features, Medscape, 21 Jan. 2021, emedicine.medscape.com/article/855644-overview#a7.</ref>

==Model==

Using gene transfer of SV40 large T-antigen in neuronal precursor cells of rats, a brain tumor model was established. The PNETs were histologically indistinguishable from the human counterparts and have been used to identify new genes involved in human brain tumor carcinogenesis.<ref name="pmid8129041">{{cite journal |author=Eibl RH, Kleihues P, Jat PS, Wiestler OD |title=A model for primitive neuroectodermal tumors in transgenic neural transplants harboring the SV40 large T antigen |journal=Am. J. Pathol. |volume=144 |issue=3 |pages=556–64 |date=March 1994 |pmid=8129041 |pmc=1887088 |doi= |url=}}</ref> The model was used to confirm p53 as one of the genes involved in human medulloblastomas, but since only about 10% of the human tumors showed mutations in that gene, the model can be used to identify the other binding partners of SV40 Large T- antigen, other than p53.<ref name="pmid1933879">{{cite journal |author=Ohgaki H, Eibl RH, Wiestler OD, Yasargil MG, Newcomb EW, Kleihues P |title=p53 mutations in nonastrocytic human brain tumors |journal=Cancer Res. |volume=51 |issue=22 |pages=6202–5 |date=November 1991 |pmid=1933879 |doi= |url=http://cancerres.aacrjournals.org/cgi/pmidlookup?view=long&pmid=1933879}}</ref>

==See also==

* [[Medulloblastoma]]

*[[Ewing family of tumors]]

* [[Ependymoma]]

PNET belongs to the* [[Ewing family of tumors]].

*[[medulloblastoma]]

==References==

{{reflist|2Reflist}}

{{Medical resources

| DiseasesDB = 31470 |

| ICD10 = |

| ICD9 = |

| ICDO = {{ICDO|9473|3}}

| OMIM =

| MedlinePlus =

| eMedicineSubj = ped |

| eMedicineTopic = 2589 |

| eMedicine_mult = {{eMedicine2|neuro|326}} |

| MeshID = D018242

}}

{{Nervous tissue tumors}}

{{Osseous and chondromatous tumors}}

{{Small blue round cell tumors}}

[[Category:PediatricsPediatric cancers]]

[[Category:Rare cancers]]

[[Category:Nervous system neoplasia]]

[[Category:Small -blue -round -cell tumortumors]]