title: Necrotizing neurosarcoidosis of the cranial base resembling an en plaque sphenoid wing meningioma: case report.
abstract: OBJECTIVE
  Necrotizing sarcoid granuloma (NSG) has been recognized as a histological variant of sarcoidosis. Two cases of neurosarcoidosis (NS) with NSG with concomitant systemic disease have been described previously. We present an unusual case of primary NS-NSG that resembled an en plaque cranial base meningioma.
  
  
  METHODS
  A 51-year-old man presented with a 3-month history of progressive left visual deterioration and proptosis. Brain magnetic resonance imaging demonstrated a large cranial base lesion occupying the left anterior clinoid process and sphenoid wing, extending to the left frontotemporal convexity. A second dura-based lesion was observed in the right parietal convexity. Both lesions enhanced homogeneously after administration of intravenous contrast medium. Magnetic resonance imaging characteristics were consistent with a typical clinoidal meningioma with an en plaque extension laterally.
  
  
  METHODS
  A left frontotemporal craniotomy with extradural removal of the anterior clinoid process was performed. When the dura was opened, a red fibrous mass was identified. Intraoperative histological analysis revealed the presence of necrotizing and noncaseating granulomas. Postoperatively, cerebrospinal fluid, erythrocyte sedimentation rate, C-reactive protein, and serum and cerebrospinal fluid angiotensin-converting enzyme values were normal. The search for acid-fast bacilli or fungi was negative. A diagnosis of primary NS-NSG was made. The patient began long-term high-dose corticosteroid therapy. One and a half years after surgery, his vision had improved significantly and the lesions were stable as revealed by magnetic resonance imaging.
  
  
  CONCLUSIONS
  The first case of primary NS-NSG in the absence of systemic sarcoidosis is reported. NS should be included in the differential diagnosis of dura-based lesions resembling meningioma.
authors.affiliation: Department of Neurosurgery, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
authors.forename: Samuel
authors.initials: S
authors.lastname: Tobias
authors.forename: Richard A
authors.initials: RA
authors.lastname: Prayson
authors.forename: Joung H
authors.initials: JH
authors.lastname: Lee
mesh_terms: D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000175:diagnosis*; D008579:Meningioma / Q000175:diagnosis*; D008875:Middle Aged; D009422:Nervous System Diseases / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D012507:Sarcoidosis / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D019291:Skull Base / Q000473:pathology / Q000601:surgery