title: Acute megakaryoblastic leukemia in Down syndrome: orbital infiltration.
abstract: OBJECTIVE
  To describe an uncommon ocular presentation of acute megakaryoblastic leukemia in a child with Down syndrome.
  
  
  METHODS
  Case report. Initial manifestation of disease was bilateral proptosis with secondary exposure keratitis caused by leukemic infiltration of the orbits.
  
  
  RESULTS
  Bone marrow biopsy and immunophenotyping established the diagnosis of acute megakaryoblastic leukemia (FAB-M7). The leukemia was treated successfully with chemotherapy, with resolution of proptosis. The patient remained in remission more than 1 year after cessation of treatment.
  
  
  CONCLUSIONS
  Bilateral proptosis can be a presenting sign of acute megakaryoblastic leukemia, a malignancy associated with Down syndrome.
authors.affiliation: Ophthalmology Rocky Mountain Lions Eye Institute, Denver, Colorado, 80262, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Olson
authors.forename: M J
authors.initials: MJ
authors.lastname: May
authors.forename: L
authors.initials: L
authors.lastname: Stork
authors.forename: N
authors.initials: N
authors.lastname: Kadan
authors.forename: J B
authors.initials: JB
authors.lastname: Bateman
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use; D004314:Down Syndrome / Q000150:complications*; D005094:Exophthalmos / Q000175:diagnosis / Q000209:etiology; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D007634:Keratitis / Q000175:diagnosis / Q000209:etiology; D007947:Leukemia, Megakaryoblastic, Acute / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D009918:Orbital Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D014057:Tomography, X-Ray Computed
chemical_list: D000970:Antineoplastic Agents