title: [CT and MRI features of peripheral primitive neuroectodermal tumor].
abstract: OBJECTIVE
  It's difficult to distinguish peripheral primitive neuroectodermal tumor (PNET) from other small round cell tumors such as Ewing's sarcoma by histological examination. This study was to analyze the CT and MRI features of peripheral PNET.
  
  
  METHODS
  The CT and MRI records of 7 patients with pathologically proved peripheral PNET were reviewed.
  
  
  RESULTS
  The tumors were located in the left ala nasi, right lower jaw bone, left chest wall, right chest wall, left spermatic cord, paraspinal, and lumbar vertebral canal. The tumors in soft tissue showed resembled non-calcified, ill-defined soft tissue masses with cystic or necrotic areas on CT images, with heterogeneous enhancement on contrast images. The tumors in the bone showed lytic lesions with large soft tissue masses on CT images. The tumors in the paraspinal and vertebral canal showed well-defined soft tissue masses without involving cord and cauda equine on MRI, and showed isointensity or hypointensity on T1WI and isointensity or hyperintensity on T2WI.
  
  
  CONCLUSIONS
  The imaging features of peripheral PNET are non-specific. CT and MRI are useful in delineating the extent, finding distant metastasis, predicting respectability and monitoring treatment of peripheral PNET.
authors.affiliation: State Key Laboratory of Oncology in South China, Guangzhou, Guangdong 510060, P. R. China. dongw.z@163.com
authors.forename: Wei-Dong
authors.initials: WD
authors.lastname: Zhang
authors.forename: Chuan-Miao
authors.initials: CM
authors.lastname: Xie
authors.forename: Yun-Xian
authors.initials: YX
authors.lastname: Mo
authors.forename: Jia-Yao
authors.initials: JY
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D005834:Genital Neoplasms, Male / Q000000981:diagnostic imaging; D006801:Humans; D007573:Jaw Neoplasms / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D009364:Neoplasm Recurrence, Local; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000473:pathology; D012189:Retrospective Studies; D013085:Spermatic Cord / Q000000981:diagnostic imaging; D013115:Spinal Canal; D013125:Spinal Neoplasms / Q000175:diagnosis*; D013899:Thoracic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D014057:Tomography, X-Ray Computed; D055815:Young Adult