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 Led to the Patient's Blindness and, Secondarily, to His Death?

Where did this case go wrong? How could a patient have gone blind in one eye and then in the other in this era of effective therapies for GCA? The crux of the matter is this: the clinicians placed too much emphasis on the finding of negative temporal artery biopsy results. The key diagnostic test was not the temporal artery biopsy specimens; rather, it was the patient's history. Evidence of GCA in the patient's history was substantial (if not overwhelming) at the time of his first episode of vision loss. Failure to place sufficient weight on that history and the existing clinical evaluation led to the cessation of glucocorticoid therapy that very likely would have preserved the vision in the patient's remaining good eye.

Let us review the evidence. At the time of the patient's first episode of vision loss, he had experienced new headaches that were atypical for him, diplopia and jaw claudication. In addition, he had normochromic, normocytic anaemia and marked elevation of acute-phase reactants. Finally, bilateral AION was confirmed by fluorescein angiography. Although correct diagnosis often seems all too easy in retrospect, substantial evidence of GCA was discarded because of negative temporal artery biopsy results, and the diagnosis was simply missed—very much to the patient's detriment.

The take-home lesson is that, in the end, GCA is a clinical diagnosis not a pathological one. Clinicians always feel reassured by a positive temporal artery biopsy, but in reality they may not have the benefit of that confirmation. Therefore, it is important to understand what temporal artery biopsies can tell us and why they often fall short of our expectations.

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