Which statement about diagnostic tests for giant cell arteritis is true?

Which statement about diagnostic tests for giant cell arteritis is true?

• A. Chest X-ray is the standard diagnostic tool
• B. Temporal artery biopsy is used to diagnose GCA
• C. ESR is never elevated in GCA
• D. CRP is never elevated in GCA

Answer: (B)

In giant cell arteritis, the key diagnostic step is obtaining tissue from the temporal artery to look for the actual inflammation in the vessel wall. This biopsy can show granulomatous inflammation with multinucleated giant cells and disruption of the internal elastic lamina, which provides histologic confirmation that the process is vasculitis affecting the temporal arteries. That direct evidence is why this test is used to diagnose GCA. There are important caveats to keep in mind. The inflammation can be segmental, so a negative biopsy doesn’t completely rule out the disease, and clinical judgment plus imaging support are often used in practice. Chest X-ray isn’t a standard diagnostic tool for GCA, and inflammatory markers like ESR and CRP are usually elevated in GCA (though not in every case), so statements claiming they are never elevated are incorrect.

In giant cell arteritis, the key diagnostic step is obtaining tissue from the temporal artery to look for the actual inflammation in the vessel wall. This biopsy can show granulomatous inflammation with multinucleated giant cells and disruption of the internal elastic lamina, which provides histologic confirmation that the process is vasculitis affecting the temporal arteries. That direct evidence is why this test is used to diagnose GCA.

There are important caveats to keep in mind. The inflammation can be segmental, so a negative biopsy doesn’t completely rule out the disease, and clinical judgment plus imaging support are often used in practice.

Chest X-ray isn’t a standard diagnostic tool for GCA, and inflammatory markers like ESR and CRP are usually elevated in GCA (though not in every case), so statements claiming they are never elevated are incorrect.