title: The thymus in Langerhans' cell histiocytosis.
abstract: OBJECTIVE
  To determine the frequency of thymic involvement in Langerhans' cell histiocytosis and describe its imaging appearance before and after treatment.
  
  
  METHODS
  A retrospective review of the radiology and clinical records of all patients diagnosed with Langerhans' cell histiocytosis at DeVos Children's Hospital between 1992 and 1998.
  
  
  RESULTS
  Of the 14 patients diagnosed with Langerhans' cell histiocytosis, 7 demonstrated multisystem involvement. The thymus was involved in 5 of 7 patients. The thymus was enlarged in 5; thymic contours were nodular/lobulated in 2; cystic changes were noted in 4; and dystrophic vascular-appearing calcifications were seen in 1. In all cases, findings regressed or resolved following chemotherapy.
  
  
  CONCLUSIONS
  The thymus is commonly involved in Langerhans' cell histiocytosis, especially in multisystem disease. Radiologically, the thymus is enlarged and may be smooth or lobulated/nodular in contour, possibly containing cysts and calcifications.
authors.affiliation: DeVos Children's Hospital, Grand Rapids, MI 49503, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Junewick
authors.forename: N E
authors.initials: NE
authors.lastname: Fitzgerald
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006646:Histiocytosis, Langerhans-Cell / Q000000981:diagnostic imaging*; D006801:Humans; D007223:Infant; D008297:Male; D013902:Radiography, Thoracic; D012189:Retrospective Studies; D013950:Thymus Gland / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed