出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2017/08/31 03:27:09」(JST)
Primitive neuroectodermal tumor | |
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Micrograph of an H&E stained section of a peripheral PNET. | |
Classification and external resources | |
ICD-O | M9473/3 |
DiseasesDB | 31470 |
eMedicine | ped/2589 neuro/326 |
MeSH | D018242 |
[edit on Wikidata]
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Primitive neuroectodermal tumor (PNET) is a malignant (cancerous) neural crest tumor.[1] 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%.[2]
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.
It is classified into two types, based on location in the body: peripheral PNET and CNS PNET.
The peripheral PNET (pPNET) is now thought to be virtually identical to 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."[3]
PNET of the CNS generally refer to supratentorial PNETs.
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.[4] 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.[5]
Nervous tissue tumors/NS neoplasm/Neuroectodermal tumor (ICD-O 9350–9589) (C70–C72, D32–D33, 191–192/225)
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Endocrine |
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CNS |
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PNS: NST |
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Note: Not all brain tumors are of nervous tissue, and not all nervous tissue tumors are in the brain (see brain metastasis).
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Tumours of bone and cartilage (ICD-O 9180–9269) (C40–C41/D16, 170/213)
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Diaphysis |
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Metaphysis |
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Epiphysis |
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Other/ungrouped |
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Small-blue-round-cell tumors
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リンク元 | 「ユーイング肉腫」「髄芽腫」「原始神経外胚葉性腫瘍」「PNET」「spongioblastoma」 |
拡張検索 | 「peripheral primitive neuroectodermal tumor」「cerebral primitive neuroectodermal tumor」「primitive neuroectodermal tumors」 |
関連記事 | 「primitive」「tumor」 |
骨肉腫 | ユーイング肉腫 | |
概念 | 類骨を形成する悪性骨腫瘍 骨組織に原発し、腫瘍細胞が直接類骨あるいは骨組織を形成する。 |
分化の高悪性度小円形細胞肉腫。発生母細胞は神経外胚葉 |
疫学 | 15歳ピーク 10歳代:60% 20歳代:15% 男性にやや多い |
10-30歳で見られるが、10代から10代未満に好発し、80%が20歳以下である。骨肉腫より若年者に好発する。 男女比 = 2:1 |
原発性悪性骨腫様のなかで最多 | 骨肉腫、骨髄腫、軟骨肉腫に次いで多い。 | |
好発部位 |
大腿骨遠位 脛骨近位 合わせて75% 次いで上腕骨近位 |
長幹骨の骨幹部 骨盤、大腿骨、上腕骨、脛骨の順に好発する |
症状 | 腫脹、疼痛、腫瘍の増大で発赤、局所熱感、静脈怒張 | 疼痛、腫脹、全身症状(白血球増多、発熱) |
血液検査 | 血清アルカリフォスファターゼ、乳酸脱水素酵素 | 白血球増多、CRP上昇、赤沈亢進 |
単純X線写真 | 骨硬化を伴わない骨破壊、種々の程度の腫瘍性骨新生(境界不明瞭の淡い綿花様、綿球様の骨硬化) 外骨膜反応(コットマン三角、スピクラ形成) |
骨皮質を破壊しつくす前にフォルクマン管を介して軟部組織に浸潤し骨外に浸潤する。このために骨膜を持ち上げ骨膜反応(たまねぎの皮様(onion skin appearance))を呈する。 斑点状、蚕喰状の骨吸収破壊像 |
転移 | 血行性、肺転移 | |
予後 | 5年生存率50-70% | 予後不良 日本での5年累積生存率は45% |
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