title: Imaging features of undifferentiated embryonal sarcoma of the liver: a series of 15 children.
abstract: BACKGROUND
  Undifferentiated embryonal sarcoma of the liver is a rare malignant mesenchymal tumour occurring mostly in children ages 6-10 years. The discrepancy between its solid appearance on US and cystic-like appearance on CT has been described.
  
  
  OBJECTIVE
  To study the imaging particularities and similarities among our cases of undifferentiated embryonal sarcoma and to report the errors in initial diagnoses.
  
  
  METHODS
  We conducted a retrospective study of 15 children with undifferentiated embryonal sarcoma diagnosed or referred to our hospital during 1997-2015 and analysed the clinical, biological and imaging data.
  
  
  RESULTS
  We identified eight boys and seven girls ages 9 months to 14 years. Ten children presented with abdominal pain. Alpha-fetoprotein was slightly increased in one. Initial US and CT had been performed for all, while additional MRI had been done in two children. Initial CT demonstrated a hypoattenuated mass in all. Rupture was seen in five and intratumoural bleeding in seven children. Tumour volumes reduced during neoadjuvant chemotherapy in 10 children.
  
  
  CONCLUSIONS
  Undifferentiated embryonal sarcoma might be suggested in a non-secreting unifocal tumour with well-defined borders, fluid-filled spaces on US, hypoattenuation and serpiginous vessels on CT, and if there are signs of internal bleeding or rupture on CT or MRI.
authors: Department of Pediatric Radiology, Bicêtre Hospital, 78, rue du Général Leclerc, Le Kremlin-Bicêtre, 94275, France. flaviugabor@yahoo.com.
authors: Flaviu
authors: F
authors: Gabor
authors: Department of Pediatric Radiology, Bicêtre Hospital, 78, rue du Général Leclerc, Le Kremlin-Bicêtre, 94275, France.
authors: Stephanie
authors: S
authors: Franchi-Abella
authors: Unit of Hepato-Biliary and Transplant Surgery, Department of Surgery and Transplantation Centre, Bambino Gesù Children's Hospital, Rome, Italy.
authors: Laura
authors: L
authors: Merli
authors: Department of Pediatric Radiology, Bicêtre Hospital, 78, rue du Général Leclerc, Le Kremlin-Bicêtre, 94275, France.|Faculty of Medicine, Paris Sud University, Le Kremlin-Bicêtre, France.|LTCI, CNRS, Télécom Paris Tech, Université Paris-Saclay, Paris, France.
authors: Catherine
authors: C
authors: Adamsbaum
authors: Department of Pediatric Radiology, Bicêtre Hospital, 78, rue du Général Leclerc, Le Kremlin-Bicêtre, 94275, France.
authors: Daniele
authors: D
authors: Pariente
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008099:Liver / Q000000981:diagnostic imaging; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D009373:Neoplasms, Germ Cell and Embryonal / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D012509:Sarcoma / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography
keywords: Children; Computed tomography; Cystic mesenchymal tumour; Liver tumour; Magnetic resonance imaging; Sarcoma; Ultrasound