Rate of Discordant Findings in Bilateral Temporal Artery Biopsy to Diagnose Giant Cell Arteritis

Objective. To determine to what extent performing simultaneous bilateral temporal artery biopsies might increase the diagnostic sensitivity in giant cell arteritis (GCA). Methods. In total 173 consecutive pathology reports of temporal artery biopsies were reviewed for histological findings by a single pathologist. The rate of discordance of biopsy results was calculated in patients with GCA. Results. Biopsies were performed bilaterally and simultaneously in 132 cases;, 51 had positive results. In 38 the biopsy was positive on both sides (concordant results), while in 13 patients only one side was positive (discordant results), reaching a discordance rate of 13/51 = 0.255. Therefore 12.7% of the patients (one-half of the discordance rate) could have been misdiagnosed as biopsy-negative had a biopsy been done only unilaterally in those 51 cases. Conclusion. These data suggest that performing bilateral temporal artery biopsies increases the diagnostic sensitivity of the procedure by up to 12.7%, compared to unilateral biopsies. (First Release Feb 15 2009; J Rheumatol 200936:794-6; doi: 10.3899/jrheum.080792)