If you have symptoms of giant cell arteritis (GCA) and your doctor believes you may have it, he or she may order a temporal artery biopsy to make sure.
Giant cell arteritis can occur at various points along an artery. To test for giant cell arteritis, your doctor may have a surgeon take a sample of a blood vessel on your temple and test it for inflammation.
If a temporal artery biopsy shows no signs of inflammation but your symptoms strongly suggest giant cell arteritis, you and your doctor will discuss the risks and benefits of treatment and of no treatment. You and your doctor will decide whether or not you will proceed with treatment.
If you are taking high-dose corticosteroids, the biopsy result may not be accurate. In this case, any biopsy testing must be performed as soon as possible, preferably within 2 to 5 days. Biopsies done more than about a week after the start of high-dose corticosteroids may be falsely normal (false-negative).