title: Pulmonary Langerhans cell histiocytosis in adults: high-resolution CT-pathology comparisons and evolutional changes at CT.
abstract: OBJECTIVE
  To compare high-resolution (HR) CT and histopathological findings and to evaluate serial CT findings in pulmonary Langerhans cell histiocytosis (PLCH).
  
  
  METHODS
  We reviewed CT of lung lesions in 27 adults (M:F = 20:7, mean age, 41 ± 12.3 years) with PLCH. After evaluating lung abnormalities including nodules, micronodules, thick-walled, thin-walled, and bizarre-shaped cysts and reticulation, observers compared CT findings obtained at lung biopsy sites with histopathological findings. The final CT was compared with the initial CT to determine disease extent changes.
  
  
  RESULTS
  The most frequently observed patterns of lung abnormalities were micronodules (n = 24, 89%), thick-walled (n = 22, 82%), and thin-walled (n = 22, 82%) cysts. Even thin-walled and bizarre cysts harboured active inflammatory Langerhans cell sheets and eosinophils in their walls. In thin-walled cysts, we noted pericystic inflammatory cell infiltrations along the alveolar walls, as well as pericystic emphysema. Thin-walled or bizarre cysts demonstrated a tendency to coalesce with surrounding cysts via their cystic wall destruction. Fourteen (52%) patients showed improvement and nine (33%) showed progressing disease.
  
  
  CONCLUSIONS
  More than half of patients with pulmonary PLCH show improvement at follow-up CT. Even thin-walled cysts harbour active inflammatory cells on histopathology and exhibit improvement at follow-up CT.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, Korea.
authors.forename: Hyo Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Kyung Soo
authors.initials: KS
authors.lastname: Lee
authors.forename: Takeshi
authors.initials: T
authors.lastname: Johkoh
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Tomiyama
authors.forename: Ho Yun
authors.initials: HY
authors.lastname: Lee
authors.forename: Joungho
authors.initials: J
authors.lastname: Han
authors.forename: Tae Sung
authors.initials: TS
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D018450:Disease Progression; D005260:Female; D006646:Histiocytosis, Langerhans-Cell / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed / Q000379:methods*