title: Hypertrophic pachymeningitis as a result of a retropharyngeal inflammatory pseudotumor: case report.
abstract: OBJECTIVE
  An extremely rare case of a patient with hypertrophic pachymeningitis that resulted from an inflammatory pseudotumor of retropharynx is described.
  
  
  METHODS
  A 59-year-old man with a 9-year history of retropharyngeal inflammatory pseudotumor sought care for severe headache and multiple cranial nerve palsies. Magnetic resonance imaging and computed tomographic scans revealed pachymeningeal enhancement and obstructive hydrocephalus attributable to marked dural thickening around the foramen magnum.
  
  
  METHODS
  Decompression of the foramen magnum, C1 laminectomy, and meningeal biopsy were performed. The histological examination of the biopsy specimen revealed chronic inflammatory infiltrate in the hypertrophic dura mater. Corticosteroid pulse therapy was subsequently completed. Clinical and neuroradiological findings improved remarkably.
  
  
  CONCLUSIONS
  A new case of hypertrophic pachymeningitis as a result of a retropharyngeal inflammatory pseudotumor is presented. We review and discuss the clinical features and the pathogenic mechanisms of hypertrophic pachymeningitis.
authors.affiliation: Departments of Neuropathology and Neurosurgery, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. matsumo@np.med.kyushu-u.ac.jp
authors.forename: Kenichi
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Natori
authors.forename: Eiko
authors.initials: E
authors.lastname: Hirokawa
authors.forename: Toru
authors.initials: T
authors.lastname: Iwaki
mesh_terms: D006104:Granuloma, Plasma Cell / Q000150:complications* / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D006984:Hypertrophy; D008279:Magnetic Resonance Imaging; D008297:Male; D008581:Meningitis / Q000209:etiology* / Q000473:pathology*; D008875:Middle Aged; D010608:Pharyngeal Diseases / Q000150:complications* / Q000175:diagnosis / Q000473:pathology; D014057:Tomography, X-Ray Computed