title: Nondiagnostic Computed Tomography-guided Percutaneous Lung Biopsies Are More Likely When Infection Is Suspected.
abstract: OBJECTIVE
  The purpose of this study was to assess the incidence of nondiagnostic computed tomography-guided lung biopsy results, stratified by biopsy indication, and determine the final diagnosis in such cases.
  
  
  METHODS
  Following institutional review board approval, pathology results from CT-guided lung biopsies over a 5-year period at 2 institutions were categorized as diagnostic or nondiagnostic. Each biopsy's indication was categorized as being for a lesion considered likely to be cancer, infection, or uncertain. For all nondiagnostic biopsies, the medical chart was reviewed to determine the final clinical diagnosis.
  
  
  RESULTS
  A total of 660 biopsies were evaluated, 139 (21%) of which were nondiagnostic. Of these 139 patients, the final clinical diagnosis was infection in 37%, cancer in 30%, and a benign noninfectious diagnosis in 10%; 23% remained undiagnosed at last available follow-up. Among the patients in whom there was a high pretest suspicion for cancer, 13% were nondiagnostic, 45% of which were cancer and 27% were infection. Among biopsies of lesions with pretest probability for both cancer and infection, 51% were nondiagnostic; on clinical follow-up these were determined to be infection in 34% and cancer in 14%. When there was high pretest suspicion for infection, 73% were nondiagnostic, of which 13% were cancer on clinical follow-up, and 88% were infection. The rate of nondiagnostic biopsies was statistically significantly different (P<0.001) among the 3 groups.
  
  
  CONCLUSIONS
  Nondiagnostic biopsies are common and occur most frequently when there is a moderate or high pretest suspicion for infection. Among all nondiagnostic biopsies, regardless of indication, cancer and infection were diagnosed on follow-up in similar proportions.
authors.affiliation: Departments of *Radiology and Biomedical Imaging †Pathology and Laboratory Medicine, University of California, San Francisco, San Francisco, CA.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Haas
authors.forename: Brett M
authors.initials: BM
authors.lastname: Elicker
authors.forename: Janet
authors.initials: J
authors.lastname: Nguyen
authors.forename: Karen G
authors.initials: KG
authors.lastname: Ordovas
authors.forename: Kirk D
authors.initials: KD
authors.lastname: Jones
authors.forename: Travis S
authors.initials: TS
authors.lastname: Henry
authors.forename: David M
authors.initials: DM
authors.lastname: Naeger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015641:Radiography, Interventional / Q000706:statistics & numerical data*; D012141:Respiratory Tract Infections / Q000000981:diagnostic imaging* / Q000473:pathology*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*; D055815:Young Adult