title: Radiologic and clinicopathologic findings of peripheral primitive neuroectodermal tumors.
abstract: BACKGROUND
  Primitive neuroectodermal tumors (PNETs) constitute a rare type of malignant neuroectodermal tumors that have chromosomal translocations identical to Ewing's sarcoma (ES), and the characteristics of this disease remain unclear.
  
  
  OBJECTIVE
  To describe the clinical, radiological, and pathological features of peripheral PNETs (pPNETs) to enhance their recognition.
  
  
  METHODS
  The clinical, imaging, and pathologic findings of 35 patients with pPNETs were retrospectively reviewed, all being confirmed by biopsy or surgical pathology. All 35 patients had preoperative computed tomography (CT) examinations; 10 patients had preoperative magnetic resonance imaging (MRI) studies.
  
  
  RESULTS
  Of 35 pPNET patients, 54.3% had a primary tumor in soft tissue, the others in bone. On plain CT images, 33 lesions demonstrated heterogeneous hypodense masses with multiple lamellar lower density, and with osteolytic destruction if the tumor originated in bone. Calcification was only found in five lesions arising in soft tissue. All lesions enhanced heterogeneously with varying areas of cystic changes, and all lesions in bone and 52.6% of lesions in soft tissue showed ill-defined margins after contrast administration. On MRI, these tumors appeared in conjunction with osteolytic bone destruction and irregular soft tissue masses iso- to hypointense to skeletal muscle on T1-weighted images and showed heterogeneously high intensity on T2-weighted images. All lesions enhanced heterogeneously with cystic changes. Homer-Wright rosettes were observed in 15 lesions, and 97.1% lesions were positive for CD99 in histopathological results.
  
  
  CONCLUSIONS
  pPNETs can involve any part of the body, and a large, ill-defined, aggressive soft tissue mass and heterogeneous enhancement with or without osteolytic bone destruction on CT or MR images could suggest the diagnosis.
authors: Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Henan, PR China Department of Radiology, Taizhou Cancer Hospital, Zhejiang, PR China.
authors: Lei
authors: L
authors: Ba
authors: Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Henan, PR China natan2000@126.com.
authors: Hongna
authors: H
authors: Tan
authors: Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Henan, PR China.
authors: Huijuan
authors: H
authors: Xiao
authors: Department of Radiology, Taizhou Cancer Hospital, Zhejiang, PR China.
authors: Yansheng
authors: Y
authors: Guan
authors: Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Henan, PR China.
authors: Jianbo
authors: J
authors: Gao
authors: Department of Pathology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Henan, PR China.
authors: Xianzheng
authors: X
authors: Gao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007223:Infant; D007472:Iohexol / Q000031:analogs & derivatives; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000000981:diagnostic imaging* / Q000473:pathology*; D015588:Observer Variation; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012983:Soft Tissue Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide; D019786:Gadolinium DTPA
keywords: Peripheral primitive neuroectodermal tumor (pPNET); computed tomography (CT); magnetic resonance imaging (MRI); pathology