title: The filum terminale externum.
abstract: OBJECTIVE
  The filum terminale externum (FTE) is the extradural component of the filum terminale internum and little attention has been dedicated to this structure in the literature. The authors theorized that the rare intrasacral ependymomas may originate from ependymal cell collections within the FTE.
  
  
  METHODS
  To address this hypothesis, the FTE was dissected and analyzed histologically in 15 adult cadavers. None of the specimens was found to harbor ependymal or other glial cell collections.
  
  
  CONCLUSIONS
  The authors found previously undescribed smooth-muscle cells within the FTE. Furthermore, histological analysis identified adipose, nerve, bone, and cartilage cells.
authors.affiliation: Department of Cell Biology, University of Alabama at Birmingham, Alabama, USA. rstubbs@uab.edu
authors.forename: R Shane
authors.initials: RS
authors.lastname: Tubbs
authors.forename: Randall Lee
authors.initials: RL
authors.lastname: Murphy
authors.forename: David R
authors.initials: DR
authors.lastname: Kelly
authors.forename: Robert
authors.initials: R
authors.lastname: Lott
authors.forename: E George
authors.initials: EG
authors.lastname: Salter
authors.forename: W Jerry
authors.initials: WJ
authors.lastname: Oakes
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology; D000368:Aged; D000369:Aged, 80 and over; D001808:Blood Vessels / Q000033:anatomy & histology; D002420:Cauda Equina / Q000033:anatomy & histology* / Q000098:blood supply / Q000166:cytology; D005260:Female; D005347:Fibroblasts / Q000166:cytology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009130:Muscle, Smooth / Q000033:anatomy & histology