title: Tumoral calcinosis of the filum terminale.
abstract: OBJECTIVE
  Tumoral calcinosis is a rare disorder presenting with tumor-like masses of calcification, usually in soft tissues around large joints. Although this condition has been reported in the spine, this is the first reported instance of this uncommon lesion occurring in the intradural compartment, involving the filum terminale.
  
  
  METHODS
  A 55-year-old man presented with back and right leg pain. Initial investigations revealed no cause. A review of his original magnetic resonance imaging scans revealed an intradural calcified mass at L3 level. Surgical exploration was undertaken.
  
  
  METHODS
  A L3 laminectomy revealed a calcified mass adherent to the filum terminale. Frozen section from this mass revealed tumoral calcinosis involving the filum terminale.
  
  
  CONCLUSIONS
  This is the first known case of intradural involvement by tumoral calcinosis. This is an uncommon disorder, and a high index of suspicion is required to diagnose the condition, which can recur if incompletely removed.
authors.affiliation: Department of Histopathology, Aberdeen Royal Infirmary, Aberdeen, Scotland. m.sharma@abdn.ac.uk
authors.forename: M
authors.initials: M
authors.lastname: Sharma
authors.forename: R
authors.initials: R
authors.lastname: Sinha
authors.forename: K
authors.initials: K
authors.lastname: Hussey
authors.forename: I P
authors.initials: IP
authors.lastname: Fouyas
mesh_terms: D002114:Calcinosis / Q000601:surgery*; D002420:Cauda Equina / Q000473:pathology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007592:Joint Diseases / Q000503:physiopathology*; D007796:Laminectomy / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008875:Middle Aged; D013122:Spinal Diseases / Q000601:surgery*
chemical_list: D005904:Glial Fibrillary Acidic Protein