How would you approach management of a patient with classic GCA symptoms, elevated ESR and improvement with steroids, but negative temporal artery biopsy and CTA imaging without evidence of vasculitis?

This is a difficult clinical situation, but one that comes up frequently. In the Olmsted County population-based cohort study, about 14% of patients had a clinical diagnosis of GCA (biopsy negative, imaging negative, or not done, Garvey et al., PMID 34644662).

I would want to make sure that GCA mimic...

No imaging modality is 100% accurate. TA biopsies may be negative for a variety of reasons, including skip lesions and biopsies that are too short < 1 cm. One large retrospective study of ~1200 biopsies revealed that prefixation biopsy size of 1.5-2.0cm was the optimal size. If the clinical features...