title: Radiologic and Histopathologic Features of Calcifying Pseudoneoplasm of the Neural Axis.
abstract: OBJECTIVE
  To describe the radiologic and corresponding histopathologic features of calcifying pseudoneoplasms of the neural axis.
  
  
  METHODS
  Two cases of calcifying pseudoneoplasm of the neural axis were retrospectively reviewed. The first case was documented in a 64-year-old woman, who presented with lower back pain with radiation to her left leg. The second case was documented in a 70-year-old man, who presented with headaches. Medical records, radiologic and histologic findings, and related literature were reviewed.
  
  
  RESULTS
  In the first case, imaging of the lumbar spine revealed a 3.8 × 2.2-cm calcified lesion at the level of vertebrae L5 and S1. A subsequent excision exposed an extradural lesion at L5. Histopathologic examination showed amorphous and granular calcifying material with occasional fibrohistiocytic and giant cell reaction, consistent with calcifying pseudoneoplasm of the neural axis. In the second case, imaging of the head revealed a 2.4 × 2.6-cm well-circumscribed, lobulated, calcified lesion within the basal frontal lobe. Subsequent resection exposed an intradural mass with a nodular arrangement of amorphous and granular calcifying material associated with fibrohistiocytic and giant cell reaction. Both patients had a favorable postoperative course and failed to show any clinical or radiologic sign of recurrence.
  
  
  CONCLUSIONS
  Calcifying pseudoneoplasm of the neural axis is an uncommon condition with an excellent prognosis but is often misdiagnosed due to its nonspecific clinical presentation and varied findings on radiology.
authors.affiliation: Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada. Electronic address: linda.kocovski@medportal.ca.
authors.forename: Linda
authors.initials: L
authors.lastname: Kocovski
authors.affiliation: Department of Radiology, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Naveen
authors.initials: N
authors.lastname: Parasu
authors.affiliation: Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: John P
authors.initials: JP
authors.lastname: Provias
authors.affiliation: Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Snezana
authors.initials: S
authors.lastname: Popovic
mesh_terms: D000368:Aged; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D002114:Calcinosis / Q000000981:diagnostic imaging* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000000981:diagnostic imaging* / Q000473:pathology; D012189:Retrospective Studies; D013120:Spinal Cord Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D014057:Tomography, X-Ray Computed
keywords: Calcifying pseudoneoplasm; Calcifying pseudotumour; Fibro-osseous lesion