Why Do Temporal Arteries Go Wrong?

Principles and Pearls From a Clinician and a Pathologist

Yara Banz; John H. Stone


Rheumatology. 2018;57(2):ii3-ii10. 

In This Article

What Are the Solutions?

The Growing Role of Imaging

Data from the Tocilizumab in Giant Cell Arteritis (GiACTA) trial[43] emphasize the growing role that imaging plays in the diagnosis of GCA. In that trial, 38% of patients either did not undergo temporal artery biopsy or the biopsy results were negative, highlighting the importance of imaging modalities as tools for the diagnosis of GCA. Conversely, many patients who have negative results on imaging studies will have positive temporal artery biopsy results, so the approaches to diagnosis are complementary. In some cases, neither temporal artery biopsy nor imaging yields a compelling case for the diagnosis of GCA. Therefore, advances in diagnostic imaging have supplanted pathology in a minority of GCA cases—particularly those characterized by large-vessel involvement—but temporal artery biopsy remains the mechanism of diagnostic confirmation in most patients.

Careful History Taking

For a clinician, the key diagnostic test is neither the temporal artery biopsy nor large-vessel imaging, but the patient's history; the patient's history is the clinician's scalpel and microscope. Skill in taking a patient's history is crucial to suspecting GCA in the first place and to making the decision to order temporal artery biopsy or any other test that might confirm or refute the diagnostic suspicion.


The development of a single diagnostic test that is perfect, or close to perfect, be it clinical, serological, radiological or pathological, is not imminent. Communication between clinicians, surgeons, pathologists, radiologists, imaging technicians and patients is fundamental to determining the best solution in difficult cases. The clinician must devote the time necessary to listen to the patient, and to interpret the patient's words wisely. In some cases, the clinician and radiologist can guide the surgeon with regard to the proper site for temporal artery biopsy. Following a biopsy, the likelihood of confirming or refuting the diagnosis of GCA in an accurate manner is then heightened by a process of collegial clinicopathological correlation, best conducted in person between the clinician and the pathologist sitting at two heads of the same microscope.