title: Tree-in-bud pattern in central lung cancer: CT findings and pathologic correlation.
abstract: OBJECTIVE
  Tree-in-bud (TIB) pattern can be found with central lung cancer on chest CT scans. However, few reports have described it so far. We aim to determine its incidence, CT findings and pathologic basis.
  
  
  METHODS
  652 consecutive patients with confirmed central lung cancer were enrolled in our study. The incidence, CT findings and pathologic features of TIB pattern were analyzed retrospectively.
  
  
  RESULTS
  In total, TIB pattern was found in 22.5% (147/652) of patients. It was more common in patients with squamous cell carcinoma than those with non-squamous cell carcinoma (P=0.000). The most important associated CT finding was obstructive bronchial mucoid impaction distal to the cancer (100%, 147/147), followed by consolidation and ground-glass opacities (62.6%, 92/147). TIB pattern was confined to the areas of lung supplied by the involved bronchi (100%, 147/147) and had a focal distribution predominantly (94.6%, 139/147). Pathologically, it correlated with bronchiolectasis, bronchiolar lumen filled by mucus and inflammatory exudates, wall thickening with inflammatory cells infiltration.
  
  
  CONCLUSIONS
  TIB pattern is commonly detected in central lung squamous cell carcinoma on thoracic CT scan. It usually has a localized distribution with a predominant associated CT finding of obstructive bronchial mucoid impaction. This pattern corresponds to the mucoid impaction of bronchioles and bronchiolitis pathologically. A full understanding of TIB pattern in central lung cancer can be useful in preventing diagnostic errors.
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Radiology, Children's Hospital of Chongqing Medical University, No. 136 Zhongshan Road Two, Yuzhong District, Chongqing, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Fan
authors.affiliation: Department of Radiology, The Fifth People's Hospital of Chongqing, No. 24 Renji Road, Nan'an District, Chongqing, China.
authors.forename: Xing-Tao
authors.initials: XT
authors.lastname: Huang
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing, China. Electronic address: ltycqfs@126.com.
authors.forename: Tian-You
authors.initials: TY
authors.lastname: Luo
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing, China.
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Chu
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing, China.
authors.forename: Li
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing, China.
authors.forename: Zhi-Wei
authors.initials: ZW
authors.lastname: Zhang
authors.affiliation: Department of Pathology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing, China.
authors.forename: Yan-Qing
authors.initials: YQ
authors.lastname: Li
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing, China.
authors.forename: Jing-Quan
authors.initials: JQ
authors.lastname: Wu
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ouyang
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing, China.
authors.forename: Fa-Jin
authors.initials: FJ
authors.lastname: Lv
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing, China.
authors.forename: Chao-Hao
authors.initials: CH
authors.lastname: Ma
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed
keywords: Bronchial mucoid impaction; Computed tomography; Lung cancer; Pathological; Squamous cell carcinoma; Tree-in-bud pattern