title: Benign notochordal cell tumors of the spine: natural history of 8 patients with histologically confirmed lesions.
abstract: BACKGROUND
  Notochord-related lesions of the spinal column include benign notochordal cell tumors (BNCTs), ecchordosis physaliphora, both generally considered benign lesions, and chordomas, which represent malignant tumors. The histological similarity of these lesions to the notochord and each other and their strong predilection to the axial skeleton have led to the hypothesis that these lesions represent a continuum of malignant transformation from notochordal remnants, BNCTs, and finally chordomas.
  
  
  OBJECTIVE
  To present a cohort of biopsy-proven BNCTs with a description of radiographic features, histology, and follow-up to help elucidate the optimal management of these lesions.
  
  
  METHODS
  A retrospective chart review identified 13 patients with notochordal rest lesions confirmed by histology. Histologic inclusion criteria included notochordal features without evidence of septation, myxoid matrix, nuclear atypia, or mitotic figures. Tumors exhibiting evidence of cortical expansion or destruction were excluded. The natural history and histological and radiographic features were examined.
  
  
  RESULTS
  Sixteen spinal lesions from 8 patients met the diagnostic criteria for BNCTs, identified on imaging after the patient presented with back pain. Radiographically, all lesions were hypointense on T1-weighted magnetic resonance imaging sequences and hyperintense on T2-weighted and short T1 inversion recovery. The median radiographic follow-up was 21.6 months (range, 8.5-71.2 months). None of the lesions exhibited radiographic or symptomatic progression.
  
  
  CONCLUSIONS
  Although limited by short follow-up, our series confirms that these lesions may be safely observed without evidence of malignant transformation, which emphasizes the importance of distinction of BNCT from chordoma at diagnosis and the possibility of close follow-up for these lesions instead of aggressive treatment indicated in patients with chordomas.
authors.affiliation: Department of Neurosurgery, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.
authors.forename: J Bryan
authors.initials: JB
authors.lastname: Iorgulescu
authors.forename: Ilya
authors.initials: I
authors.lastname: Laufer
authors.forename: Meera
authors.initials: M
authors.lastname: Hameed
authors.forename: Patrick
authors.initials: P
authors.lastname: Boland
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Yamada
authors.forename: Eric
authors.initials: E
authors.lastname: Lis
authors.forename: Mark
authors.initials: M
authors.lastname: Bilsky
mesh_terms: D000328:Adult; D000368:Aged; D002817:Chordoma / Q000473:pathology* / Q000503:physiopathology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009672:Notochord / Q000473:pathology*; D012189:Retrospective Studies; D013125:Spinal Neoplasms / Q000473:pathology* / Q000503:physiopathology*; D014057:Tomography, X-Ray Computed