title: Clinical and pathological features of adult pulmonary tuberculosis with reversed halo sign.
abstract: OBJECTIVE
  To understand the pathological correlation of the reversed halo sign (RHS) in adult pulmonary tuberculosis (PTB) patients, and to compare the clinical characteristics of PTB patients with RHS with those without RHS.
  
  
  METHODS
  The study included 80 patients consecutively diagnosed with PTB by pathology or smear-positive sputum or bronchoalveolar lavage fluid from 1 January to 31 August 2012. All patients underwent high-resolution computed tomography (HRCT) scan, and were divided into two groups based on HRCT findings: RHS and non-RHS. All patients in the RHS group underwent CT-guided transthoracic lung biopsy to evaluate histopathological abnormalities. Clinical features such as smoking history, TB-related symptoms and comorbidities were compared.
  
  
  RESULTS
  The 'ring' in the RHS corresponded to granulomata, with or without acid-fast stain positivity, and with or without caseating necrosis. Compared with the non-RHS group, patients in the RHS group were significantly younger, were less likely to have a smoking history and had fewer TB-related symptoms and comorbidities.
  
  
  CONCLUSIONS
  Our study shows that younger PTB patients with relatively better baseline status tended to present with RHS on HRCT, have fewer TB-related symptoms and present atypically.
authors.affiliation: Department of Respiratory and Critical Care Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China; Beijing Key Laboratory of Respiratory and Pulmonary Circulation, Beijing Institute of Respiratory Medicine, Beijing, China.
authors.forename: X
authors.initials: X
authors.lastname: Zhan
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.forename: M-L
authors.initials: ML
authors.lastname: Jin
authors.forename: M
authors.initials: M
authors.lastname: Liu
authors.forename: W-H
authors.initials: WH
authors.lastname: Chen
authors.forename: H-P
authors.initials: HP
authors.lastname: Dai
mesh_terms: D000328:Adult; D001706:Biopsy; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D005260:Female; D015769:Granuloma, Respiratory Tract / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000382:microbiology / Q000473:pathology; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000382:microbiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D009336:Necrosis; D011237:Predictive Value of Tests; D013902:Radiography, Thoracic / Q000379:methods; D012307:Risk Factors; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000382:microbiology / Q000473:pathology; D055815:Young Adult