title: Primary Leptomeningeal Gliomatosis in Children and Adults: A Morphological and Molecular Comparative Study With Literature Review.
abstract: BACKGROUND
  Primary leptomeningeal gliomatosis (PLG) is a poorly recognized tumor of the central nervous system.
  
  
  OBJECTIVE
  To describe the histopathological, immunohistochemical, and molecular features of PLG.
  
  
  METHODS
  Results of our multicentric retrospective study of 6 PLG cases (3 pediatric and 3 adult) were compared with literature data.
  
  
  RESULTS
  The mean age was 54.7 years for adults and 8.7 years for children, with 3 males and 3 females. Clinical symptoms were nonspecific. Cerebrospinal fluid analyses showed a high protein level often associated with pleocytosis but without neoplastic cells. On neuroimaging, diffuse leptomeningeal enhancement and hydrocephalus were observed, except in 1 case. PLG was mostly misinterpreted as infectious or tumoral meningitis. The first biopsy was negative in 50% of cases. Histopathologically, PLG cases corresponded to 1 oligodendroglioma without 1p19q codeletion and 5 astrocytomas without expression of p53. No immunostaining for IDH1R132H and no mutations of IDH1/2 and H3F3A genes were found. Overall survival was highly variable (2-82 months) but seems to be increased in children treated with chemotherapy.
  
  
  CONCLUSIONS
  This study shows the difficulties of PLG diagnosis. The challenge is to achieve an early biopsy to establish a diagnosis and to begin a treatment, but the prognosis remains poor. PLG seems to have a different molecular and immunohistochemical pattern compared with intraparenchymal malignant gliomas.
authors.affiliation: *Department of Pathology, Lariboisière Hospital, Paris, France; ‡Department of Pathology, La Timone, Marseille, France; §Department of Neuropathology, Sainte-Anne's Hospital, Paris, France; ¶Department of Pathology, Charles Nicolle Hospital, Rouen, France; ‖Department of Neuropediatry, La Timone, Marseille, France; #Department of Neurology, Jean Minjoz Hospital, Besançon, France; **Department of Pathology, Jean Minjoz Hospital, Besançon, France; ‡‡Department of Neuropediatry, Necker Hospital, Paris, France; §§Department of Oncology, Rennes Hospital, Rennes, France; ¶¶Department of Oncology, Gustave Roussy Institute, Paris, France; ‖‖Department of Pathology, Rennes Hospital, Rennes, France; ##Department of Pathology, CHU Est Lyon, Bron, France.
authors.forename: Arnault
authors.initials: A
authors.lastname: Tauziede-Espariat
authors.forename: Andre
authors.initials: A
authors.lastname: Maues de Paula
authors.forename: Melanie
authors.initials: M
authors.lastname: Pages
authors.forename: Annie
authors.initials: A
authors.lastname: Laquerriere
authors.forename: Emilie
authors.initials: E
authors.lastname: Caietta
authors.forename: Benoit
authors.initials: B
authors.lastname: Delpont
authors.forename: Gabriel
authors.initials: G
authors.lastname: Viennet
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Medeiros de Bustos
authors.forename: Thierry
authors.initials: T
authors.lastname: Moulin
authors.forename: Christine
authors.initials: C
authors.lastname: Barnerias
authors.forename: Elodie
authors.initials: E
authors.lastname: Vauleon
authors.forename: Jacques
authors.initials: J
authors.lastname: Grill
authors.forename: Dan
authors.initials: D
authors.lastname: Chiforeanu
authors.forename: Alexandre
authors.initials: A
authors.lastname: Vasiljevic
authors.forename: Pascale
authors.initials: P
authors.lastname: Varlet
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D055756:Meningeal Carcinomatosis / Q000175:diagnosis* / Q000401:mortality; D018302:Neoplasms, Neuroepithelial / Q000175:diagnosis* / Q000401:mortality; D059906:Neuroimaging; D011379:Prognosis; D012189:Retrospective Studies
chemical_list: D014408:Biomarkers, Tumor