title: CT and clinical findings of peripheral primitive neuroectodermal tumour in children.
abstract: OBJECTIVE
  To describe the clinical, CT and pathological findings of paediatric peripheral primitive neuroectodermal tumours (pPNETs) to enhance the recognition of these rare tumours.
  
  
  METHODS
  The clinical, CT and pathological findings of 18 paediatric patients with pPNETs confirmed by biopsy or surgical pathology were retrospectively reviewed.
  
  
  RESULTS
  The age of these 18 paediatric patients with pPNETs ranged from 4 months to 15 years, with a mean age of 7.7 years. The lesions of these 18 paediatric patients with pPNETs were located in the head and neck (n = 4), chest (n = 2), abdomen and pelvic cavity (n = 6), spine (n = 3), ilium (n = 2) and femur (n = 1). Immunohistochemical examination revealed Homer-Wright rosettes in seven lesions, and 94.4% of lesions showed consistent positive staining for CD99. On plain CT images, the majority of pPNETs showed lesions that were ill-defined (72.2%), irregularly shaped (83.3%), heterogeneous (66.7%) or hypodense masses (94.4%), and together with osteolytic bone destruction when the lesion originated in the bone. Calcifications were found in three lesions. After contrast administration, all soft-tissue masses were persistently enhanced heterogeneously with various cystic or necrotic regions, and 71.4% of them had linear enhancement. 94.4% of soft-tissue masses showed a moderate degree of enhancement. Seven cases had lymph node metastasis at diagnosis.
  
  
  CONCLUSIONS
  Paediatric pPNET can involve any part of the body, and a large, ill-defined, aggressive soft-tissue mass and moderate heterogeneous enhancement with varying cystic regions and linear enhancement, with or without osteolytic bone destruction, on CT images could suggest the diagnosis.
  
  
  CONCLUSIONS
  Primitive neuroectodermal tumours constitute a rare type of malignant neuroectodermal tumours that have chromosomal translocations identical to Ewing's sarcoma, and reports about radiological characteristics of this disease in children are insufficient. This study has described the clinical features and CT and pathological findings in 18 paediatric patients diagnosed with pPNETs in different locations, as a way to enhance the recognition of these tumours and help to differentiate from other types of paediatric malignant bone and soft-tissue tumours.
authors: 1 Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Henan, China.
authors: Huijuan
authors: H
authors: Xiao
authors: 2 Department of Hematology, Children's Hospital of Zhengzhou City, Zhengzhou, Henan, China.
authors: Fengchang
authors: F
authors: Bao
authors: 1 Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Henan, China.
authors: Hongna
authors: H
authors: Tan
authors: 1 Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Henan, China.
authors: Bo
authors: B
authors: Wang
authors: 2 Department of Hematology, Children's Hospital of Zhengzhou City, Zhengzhou, Henan, China.
authors: Wei
authors: W
authors: Liu
authors: 1 Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Henan, China.
authors: Jianbo
authors: J
authors: Gao
authors: 3 Department of Pathology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Henan, China.
authors: Xianzheng
authors: X
authors: Gao
mesh_terms: D000008:Abdominal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D000293:Adolescent; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005266:Femoral Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D007085:Ilium; D007223:Infant; D008297:Male; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000000981:diagnostic imaging* / Q000473:pathology; D012189:Retrospective Studies; D013125:Spinal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D013899:Thoracic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed