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Abstract

Primitive neuroectodermal tumours (PNETs) are a group of malignant soft tissue tumours of neuroepithelial origin that arise from primitive neural crest cells. Most of the PNETs occur in the central nervous system (CNS). If the origin is outside the CNS it is called peripheral primitive neuroectodermal tumour (pPNET). Histopathologically, PNETs consist of small round cells with a hyperchromatic nuclei, high nuclear-cytoplasmic ratio and varying degrees of neural differentiation detectable by immunohistochemical or ultrastructural techniques. pPNETs occur predominantly in children and young adults and show no gender difference. Occurrences of pPNETs in the orbit are infrequent and to the best of our knowledge only eighteen cases have been reported in the literature up to now. In this study, we present clinic, radiologic and histopathologic features of an orbital mass in an 8-year-old boy, which was diagnosed as a primary orbital pPNET confirmed by immunohistochemistry.

Keywords

• Pediatric, Peripheral primitive neuroectodermal tumour, Orbita

Çok nadir bir pediatrik periferik primitif nöroektodermal tümör vakası: Orbital primitif nöroektodermal tümör

Abstract

Primitif nöroektodermal tümörler (PNET) primitif nöral krest hücrelerinden köken alan bir grup malign yumuşak doku tümörleridir. Tümör, santral sinir sistemi ya da beyin dışındaki yumuşak dokulardan köken alırsa, periferik primitif nöroektodermal tümör (pPNET) adını almaktadır. Histopatolojik olarak PNET hiperkromatik nükleuslu, yüksek nükleus/stoplazma oranına sahip, immünohistokimyasal ve/veya ultrastrüktürel teknikler ile saptanabilen değişik derecelerde nöral diferansiasyona sahip küçük yuvarlak hücrelerden oluşmaktadır. pPNET genellikle genç erişkin ve çocuklarda ortaya çıkmakta olup cinsiyet ayrımı göstermez. Orbital yerleşim nadir izlenmektedir ve şimdiye kadar, literatürde yalnızca on sekiz vaka bildirimine ulaşılmaktadır. Biz, bu çalışmamızda immunohistokimyasal olarak pPNET tanısı onaylanmış 8 yaşında erkek çocuğun gözünde saptanan kitlenin klinik, radyolojik ve histopatolojik özelliklerini sunmayı amaçladık

Keywords

• Pediatrik, Periferik primitif nöroektodermal tümör, Orbita

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