title: Langerhans cell histiocytosis with orbital involvement.
abstract: OBJECTIVE
  To review three cases of Langerhans cell histiocytosis with orbital involvement that represent a significantly excessive incidence of this rare disease in one community. Current diagnostic criteria and therapeutic modalities related to Langerhans cell histiocytosis are reviewed.
  
  
  METHODS
  Case reports. We present clinical, radiologic, histopathologic, and epidemiologic information on three patients with Langerhans cell histiocytosis.
  
  
  RESULTS
  All three children, born within 18 months of one another, manifested rapidly progressive unilateral proptosis at age 2 years. By computed tomography, all had moderately enhancing lesions with involvement of the sphenoid bone and lateral orbit as well as the temporal lobe of the brain. All patients were treated with a combination of vincristine and prednisone, with variable resolution of their lesions. The occurrence of three cases in children born in Nogales, Arizona/ Mexico, suggests an incidence rate of 40 per million, which is approximately 26 times the expected rate (P = .0001).
  
  
  CONCLUSIONS
  The extraordinarily high incidence and the concentration of cases in both time and space of this cluster implies that Langerhans cell histiocytosis may be a sentinel disease for unusual environmental exposures.
authors.affiliation: Department of Ophthalmology, University of Arizona Health Sciences Center, Tucson 85719, USA. TKramer@eyes.Arizona.edu
authors.forename: T R
authors.initials: TR
authors.lastname: Kramer
authors.forename: R J
authors.initials: RJ
authors.lastname: Noecker
authors.forename: J M
authors.initials: JM
authors.lastname: Miller
authors.forename: L C
authors.initials: LC
authors.lastname: Clark
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001130:Arizona / Q000453:epidemiology; D001706:Biopsy; D002675:Child, Preschool; D005260:Female; D006646:Histiocytosis, Langerhans-Cell / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology; D006801:Humans; D007150:Immunohistochemistry; D015994:Incidence; D007223:Infant; D008800:Mexico / Q000453:epidemiology; D009915:Orbit / Q000000981:diagnostic imaging / Q000473:pathology; D009916:Orbital Diseases / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology; D011241:Prednisone / Q000008:administration & dosage; D012189:Retrospective Studies; D018426:SEER Program; D013100:Sphenoid Bone / Q000000981:diagnostic imaging / Q000473:pathology; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed; D014750:Vincristine / Q000008:administration & dosage
chemical_list: D014750:Vincristine; D011241:Prednisone