title: Radiologic findings of adult pelvis and appendicular skeletal Langerhans cell histiocytosis in nine patients.
abstract: OBJECTIVE
  The purpose of this article was to evaluate the radiologic findings of adult pelvis and appendicular skeletal Langerhans cell histiocytosis (LCH), emphasizing the CT and MR findings.
  
  
  METHODS
  The images of nine patients with pathologically proven LCH (five men and four women; mean age, 37.11 years) were retrospectively reviewed. Imaging analysis was confined to the long and flat bones. CT scans were performed in five patients and MR imaging was performed in eight. Images were assessed for the following features on CT and MRI: the location and number of lesions; the presence of cortical destruction, endosteal scalloping, and a periosteal reaction on CT or MRI; the margin of soft tissue masses, the presence of bone marrow edema, and a "budding" appearance on MRI; and the presence of sclerotic margins or septations on CT.
  
  
  RESULTS
  The involved skeletal sites were the pelvis (seven), femurs (five), humeri (two), tibias (two), fibula (one), clavicle (one), scapula (one), and sternum (one). Endosteal scalloping, a periosteal reaction, and a budding appearance were common on MRI or CT images. Although cortical destruction and the soft tissue lesion formation were rare, soft tissue masses had well-defined margins.
  
  
  CONCLUSIONS
  Endosteal scalloping and a budding appearance with a periosteal reaction on CT and MRI may be helpful signs for differentiation of LCH from malignant tumors in adults.
authors.affiliation: Department of Radiology, Pusan National University Hospital, Medical Research Institute, Busan, Korea.
authors.forename: You Seon
authors.initials: YS
authors.lastname: Song
authors.forename: In Sook
authors.initials: IS
authors.lastname: Lee
authors.forename: Jae Hyuck
authors.initials: JH
authors.lastname: Yi
authors.forename: Kil Ho
authors.initials: KH
authors.lastname: Cho
authors.forename: Do Kyung
authors.initials: DK
authors.lastname: Kim
authors.forename: Jong Woon
authors.initials: JW
authors.lastname: Song
mesh_terms: D000328:Adult; D001847:Bone Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging*; D001133:Bones of Upper Extremity / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006646:Histiocytosis, Langerhans-Cell / Q000175:diagnosis / Q000000981:diagnostic imaging*; D006801:Humans; D007867:Leg Bones / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010384:Pelvic Bones / Q000000981:diagnostic imaging* / Q000473:pathology; D014057:Tomography, X-Ray Computed