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.
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.
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.
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.
Abbreviations used in this paper:DST = dermal sinus tract; EMA = epithelial membrane antigen; LTT = long tethering tract; MM = meningocele manqué; MR = magnetic resonance; SBO = spina bifida occulta; SCM = split cord malformation; STT = short TT; UAB = University of Alabama at Birmingham; UWMS = University of Wisconsin Medical School.
Address reprint requests to: Bermans J. Iskandar, M.D., Department of Neurosurgery, University of Wisconsin Hospitals and Clinics, 600 Highland Avenue, Madison, Wisconsin 53792. email:
Martinez-LageJFEstebanJAPozaMCasasC: Congenital dermal sinus associated with an abscessed intramedullary epidermoid cyst in a child: case report and review of the literature. Childs Nerv Syst11:301–3051991
Martinez-LageJF, EstebanJA, PozaM, CasasC: Congenital dermal sinus associated with an abscessed intramedullary epidermoid cyst in a child: case report and review of the literature. 11:301–305, 1991)| false