Why Do Temporal Arteries Go Wrong?

Principles and Pearls From a Clinician and a Pathologist

Yara Banz; John H. Stone

Disclosures

Rheumatology. 2018;57(2):ii3-ii10. 

In This Article

What Are the Test Characteristics of Temporal Artery Biopsy?

Although some data (now >30 years old) suggest that the negative predictive value of bilateral temporal artery biopsy is > 90%,[4] the specificity of such a finding is probably far lower. The 90% value was derived from a retrospective study at the Mayo Clinic, in which an extremely rigorous approach to the performance of temporal artery biopsy was undertaken. Biopsies at the Mayo Clinic were performed for many decades by a single, highly experienced surgeon who routinely obtained between 3 and 4 cm of temporal artery from the symptomatic side (if symptoms were localized).[5] In addition, the contralateral side was biopsied if a frozen section failed to demonstrate GCA in the first biopsy. Unfortunately, this level of rigor is rarely achieved at most other medical institutions, and the yield of temporal artery biopsies at other centres is almost certainly far lower.

Although it would be most useful to understand both the sensitivity and the negative predictive value of temporal artery biopsy for each medical centre, we simply do not know these test characteristics because there is no true gold standard. In fact, estimates of the sensitivity of temporal artery biopsy vary greatly among studies, and high false-negative rates are commonly reported.[6–8] Many experts consider sensitivity estimates of 60–70% to be accurate, but this is only a guess. The sensitivity of temporal artery biopsy is substantially affected by many variables, which are discussed herein.

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