title: Monofocal acute inflammatory Demyelination (MAID): a unique disorder simulating brain neoplasm.
abstract: BACKGROUND
  Monofocal acute inflammatory demyelinating (MAID) lesions present as large masses that mimic brain tumors. The natural history and nosologic classification are not well defined.
  
  
  METHODS
  Five patients with MAID from our files and 4 from the literature are presented. We defined MAID as a mass-like lesion, >4 cm in diameter. Demyelination was pathologically proven in all patients.
  
  
  RESULTS
  Headaches and motor deficits were the most common presenting symptoms. Language problems and motor deficits were the most common findings on physical examination. After a median follow-up of 44 months, none of our 5 patients had multiple sclerosis. In similar cases, additional lesions indicative of multiple sclerosis developed within an average of 8 months.
  
  
  CONCLUSIONS
  It may be difficult to distinguish MAID from brain tumor. It may be that MAID represents a unique form of isolated demyelinating disease, or it may represent transition to multiple sclerosis.
authors.affiliation: Department of Neurology, Lahey Clinic Medical Center, Burlington, Mass, USA.
authors.forename: José A
authors.initials: JA
authors.lastname: Gutrecht
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Berger
authors.forename: Royden H
authors.initials: RH
authors.lastname: Jones
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Mancall
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000175:diagnosis*; D003711:Demyelinating Diseases / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis