title: Neurosarcoidosis--the great mimicker.
abstract: BACKGROUND
  Neurosarcoidosis is rare and difficult to diagnose especially in the absence of systemic involvement.
  
  
  METHODS
  A 22-year-old African-American man presented with inability to gaze laterally. He underwent magnetic resonance imaging (MRI) the day before that revealed "a 5-mm enhancing mass with surrounding edema in the pons anterior to the fourth ventricle most likely compatible with pontine glioma." CT angiography of the brain was negative. Two days later, the patient developed right facial droop. During craniotomy, a small lesion of rubbery consistency was identified at the mid-portion of the floor of the fourth ventricle. Frozen-section study came suggestive of lymphoma. Further pathological examination revealed sarcoidosis. The patient was discharged on prednisone, and he recovered quickly and completely.
  
  
  CONCLUSIONS
  Neurosarcoidosis can mimic common neurosurgical entities. It is important to keep neurosarcoidosis in mind when making the diagnosis, which often requires biopsy.
authors.affiliation: Medical Center of Central Georgia, Macon, GA 31201, USA. mswalid@yahoo.com
authors.forename: Mohammad Sami
authors.initials: MS
authors.lastname: Walid
authors.forename: Mohammed
authors.initials: M
authors.lastname: Ajjan
authors.forename: Arthur A
authors.initials: AA
authors.lastname: Grigorian
mesh_terms: D000328:Adult; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D001929:Brain Edema / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery; D003399:Craniotomy; D003937:Diagnosis, Differential; D005158:Facial Paralysis / Q000209:etiology* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011241:Prednisone / Q000627:therapeutic use; D012507:Sarcoidosis / Q000175:diagnosis* / Q000188:drug therapy / Q000601:surgery
chemical_list: D000893:Anti-Inflammatory Agents; D011241:Prednisone