title: Value of temporal artery biopsy length in diagnosing giant cell arteritis.
abstract: BACKGROUND
  Giant cell arteritis (GCA) is considered an ophthalmological emergency with severe sight and life-threatening sequelae. Temporal artery biopsy (TAB) is the current gold standard for the diagnosis of GCA; however, the required length of biopsy remains an issue of contention in the literature.
  
  
  METHODS
  Retrospective case-control study of a consecutive cohort of 545 patients who had undergone TABs across five hospitals between 1 January 1992 and 1 January 2016. In patients with either positive or negative TABs, we collected age, sex, biopsy length and erythrocyte sedimentation rate (ESR).
  
  
  RESULTS
  A total of 538 patients were included in the final analysis. Of these, 23.4% of TABs were positive, with the average length being 17.6 mm. There was a significant difference in means for positive (19.9 mm) and negative (16.8 mm) biopsies (P = 0.0009). Each millimetre increase in TAB length increased the odds of a positive TAB by 3.4% (P = 0.024). A cut-off point of ≥15 mm increased the odds of a positive TAB by 2.25 compared with a TAB <15 mm (P = 0.003). We also found that ESR ≥50 mm/h was a very strong predictor for a positive TAB result (P < 0.0001).
  
  
  CONCLUSIONS
  Biopsy length and ESR were significant predictors of a pathological diagnosis of GCA. We also found that the optimal length threshold predictive for GCA was 15 mm in order to avoid a false-negative GCA diagnosis. Although TAB remains the gold standard for diagnosis, clinicians should refer to both clinical and pathological data to guide their management.
authors: Department of Ophthalmology, Royal North Shore Hospital, Sydney, New South Wales, Australia.|Department of Opthalmology, The University of Sydney, Sydney, New South Wales, Australia.
authors: Lawrence J
authors: LJ
authors: Oh
authors: Department of Ophthalmology, Royal North Shore Hospital, Sydney, New South Wales, Australia.|Department of Opthalmology, The University of Sydney, Sydney, New South Wales, Australia.
authors: Eugene
authors: E
authors: Wong
authors: Department of Ophthalmology, Royal North Shore Hospital, Sydney, New South Wales, Australia.|Department of Opthalmology, The University of Sydney, Sydney, New South Wales, Australia.|Department of Anatomical Pathology, Royal North Shore Hospital, Sydney, New South Wales, Australia.|Cancer Diagnosis and Pathology Group, Kolling Institute of Medical Research, Royal North Shore Hospital, Sydney, New South Wales, Australia.
authors: Anthony J
authors: AJ
authors: Gill
authors: Department of Opthalmology, The University of Sydney, Sydney, New South Wales, Australia.|Department of Opthalmology, Sydney Eye Hospital, Sydney, New South Wales, Australia.
authors: Peter
authors: P
authors: McCluskey
authors: Department of Ophthalmology, Royal North Shore Hospital, Sydney, New South Wales, Australia.|Department of Opthalmology, Sydney Eye Hospital, Sydney, New South Wales, Australia.
authors: James E H
authors: JEH
authors: Smith
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy / Q000379:methods*; D016022:Case-Control Studies; D016001:Confidence Intervals; D005260:Female; D013700:Giant Cell Arteritis / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009517:New South Wales; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013699:Temporal Arteries / Q000473:pathology*
keywords: biopsy length; erythrocyte sedimentation rate; giant cell arteritis; temporal arteritis; temporal artery biopsy