title: Tethering tracts in spina bifida occulta: revisiting an established nomenclature.
abstract: OBJECTIVE
  The goal of the present study goal was to systematically confirm the previously recognized nomenclature for tethering tracts that are part of the spectrum of occult spinal dysraphic lesions.
  
  
  METHODS
  The tethering tract in 20 patients with spina bifida occulta underwent histological examination with H & E staining and epithelial membrane antigen (EMA) immunolabeling, and additional selected specimens were stained with Masson trichrome.
  
  
  RESULTS
  All tethering tracts contained fibrous connective tissue. Four tracts were lined with epithelial cells and either originated within a dermoid cyst, terminated at a skin dimple/sinus opening, or had both of these characteristics. No tethering tracts exhibited EMA positivity or meningeal elements. Although all tethering tracts originated in juxtaposition to the spinal cord, their termination sites were variable.
  
  
  CONCLUSIONS
  Based on histological findings and presumed embryological origin, the authors broadly classified tethering tracts terminating within the dura mater, epidural space, or lamina as "short tethering tracts" (STTs). The STTs occurred mostly in conjunction with split cord malformations and had a purely fibrous composition. Tethering tracts terminating superficial to the overlying lamina were classified as "long tethering tracts" (LTTs), and the authors propose that these are embryologically distinct from STTs. The LTTs were of two varieties: epithelial and nonepithelial, the former being typically associated with a skin dimple or spinal cord (epi)dermoid cyst. In fact, analysis of the data suggested that not every tethering tract terminating in or on the skin should be classified as a dermal sinus tract without histological confirmation, and because no evidence of meningeal tissue-lined tracts was detected, the use of the term "meningocele manqué" may not be appropriate.
authors: Department of Neurosurgery, University of Wisconsin Hospitals and Clinics, Madison, Wisconsin 53792, USA.
authors: Sharad
authors: S
authors: Rajpal
authors: M Shahriar
authors: MS
authors: Salamat
authors: R Shane
authors: RS
authors: Tubbs
authors: David R
authors: DR
authors: Kelly
authors: W Jerry
authors: WJ
authors: Oakes
authors: Bermans J
authors: BJ
authors: Iskandar
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004814:Epidermal Cyst / Q000473:pathology*; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016136:Spina Bifida Occulta / Q000473:pathology* / Q000601:surgery; D009626:Terminology as Topic