title: Peritumoral Citrobacter koseri abscess associated with parasagittal meningioma.
abstract: OBJECTIVE
  This is the second report of a Citrobacter-associated brain abscess in an adult and the first report of its association with an intradural tumor. Excluding those associated with trauma, neurosurgical procedures, and proximity to the skull base, only seven other cases of abscesses associated with intracranial tumors have been published. Five of seven tumor-associated abscesses with a microbiological diagnosis involved gram-negative bacteria, a finding that may indicate a predilection of these microorganisms for intracranial tumors.
  
  
  METHODS
  A 78-year-old female patient presented with a 6-month history of confusion and personality changes. Her medical history included paroxysmal atrial fibrillation and a 10-day course of high-dose dexamethasone but no other predisposing conditions for sepsis. She was afebrile, had no focal neurological deficits, and had no systemic abnormalities on examination. Computed tomographic imaging revealed a noncalcified, homogeneously enhancing, 3-cm-diameter, extra-axial tumor associated with the right anterior falx cerebri. The tumor did not extend to the skull base.
  
  
  METHODS
  At craniotomy, 10 to 20 ml of thick pus was found around the posteroinferior surface of the tumor. On extended culture, this material demonstrated Citrobacter koseri growth, which was effectively treated with ceftriaxone followed by meropenem and one repeated abscess aspiration. No systemic source of the infection was found.
  
  
  CONCLUSIONS
  The characteristic endothelial invasiveness of Citrobacter and related gram-negative bacteria may predispose to the formation of abscesses in association with intracranial tumors.
authors.affiliation: Department of Neurosurgery, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands, WA 6009, Australia. crplind@free.net.nz
authors.forename: Christopher R P
authors.initials: CR
authors.lastname: Lind
authors.forename: Kavitha
authors.initials: K
authors.lastname: Muthiah
authors.forename: Arnold P L
authors.initials: AP
authors.lastname: Bok
mesh_terms: D000368:Aged; D001922:Brain Abscess / Q000188:drug therapy / Q000209:etiology* / Q000601:surgery*; D002443:Ceftriaxone / Q000008:administration & dosage; D041041:Citrobacter koseri / Q000302:isolation & purification; D003399:Craniotomy; D004756:Enterobacteriaceae Infections / Q000150:complications / Q000188:drug therapy / Q000601:surgery*; D005260:Female; D005624:Frontal Bone / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008577:Meningeal Neoplasms / Q000150:complications / Q000382:microbiology / Q000601:surgery*; D008579:Meningioma / Q000150:complications / Q000382:microbiology / Q000601:surgery*; D000077731:Meropenem; D013845:Thienamycins / Q000008:administration & dosage
chemical_list: D013845:Thienamycins; D002443:Ceftriaxone; D000077731:Meropenem