title: The value of white blood cell count in patients with swollen discs.
abstract: BACKGROUND
  A broad differential diagnosis has to be considered in a patient with swollen discs. Myeloproliferative disorders such as leukemia and lymphoma can in rare cases cause infiltrative optic neuropathy.
  
  
  METHODS
  Two patients initially presented with slowly progressive severe visual loss. History was unremarkable except for previously noted slightly elevated white blood cell count for which - according to their general physicians - no treatment or work-up was required. At presentation, bilateral disc swelling was present. Magnetic resonance imaging showed enhancement of the entire optic nerves sparing the chiasm. No other intracranial lesion was found. Cerebrospinal fluid contained no malignant cells.
  
  
  RESULTS
  After bone marrow aspiration the diagnosis of non-Hodgkin's lymphoma and granulocytic leukemia, respectively, was made. Treatment resulted in visual recovery.
  
  
  CONCLUSIONS
  Work-up in a patient with swollen discs should always include white blood cell count. If the result is abnormal further exploration should be pursued. Elevated white blood cell count may be the only hint of optic nerve infiltration caused by a myeloproliferative disorder and its treatment can result in remarkable recovery.
authors.affiliation: Department of Ophthalmology, University Hospital Zurich, Switzerland. gabriela.wirth@usz.ch
authors.forename: M G
authors.initials: MG
authors.lastname: Wirth
authors.forename: O
authors.initials: O
authors.lastname: Bergamin
authors.forename: J S
authors.initials: JS
authors.lastname: Goede
authors.forename: K
authors.initials: K
authors.lastname: Landau
mesh_terms: D000368:Aged; D001707:Biopsy, Needle; D001853:Bone Marrow / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D017254:Leukemic Infiltration; D007958:Leukocyte Count; D007964:Leukocytosis / Q000175:diagnosis / Q000276:immunology / Q000473:pathology; D008228:Lymphoma, Non-Hodgkin / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D009898:Optic Disk / Q000473:pathology; D009900:Optic Nerve / Q000473:pathology*; D010211:Papilledema / Q000276:immunology* / Q000473:pathology; D015354:Vision, Low / Q000209:etiology / Q000473:pathology; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology