Editing Giant cell arteritis (section)

===Biopsy===
[[File:Cerebral Giant-Cell Vasculitis.jpg|thumb|Histopathology of giant cell vasculitis in a cerebral artery. Elastica-stain.]]
The [[Gold standard (test)|gold standard]] for diagnosing temporal arteritis is [[biopsy]], which involves removing a small part of the vessel under local anesthesia and examining it [[microscope|microscopically]] for [[giant cell]]s infiltrating the tissue.<ref>{{cite journal | vauthors = Cahais J, Houdart R, Lupinacci RM, Valverde A | title = Operative technique: Superficial temporal artery biopsy | journal = Journal of Visceral Surgery | volume = 154 | issue = 3 | pages = 203–207 | date = June 2017 | pmid = 28601496 | doi = 10.1016/j.jviscsurg.2017.05.001 | doi-access =  }}</ref> However, a [[false negative|negative result]] does not definitively rule out the diagnosis; since the [[blood vessel]]s are involved in a patchy pattern, there may be unaffected areas on the vessel and the biopsy might have been taken from these parts. Unilateral biopsy of a 1.5–3&nbsp;cm length is 85-90% sensitive (1&nbsp;cm is the minimum).<ref>{{cite journal | vauthors = Ypsilantis E, Courtney ED, Chopra N, Karthikesalingam A, Eltayab M, Katsoulas N, Tang TY, Ball RY | title = Importance of specimen length during temporal artery biopsy | journal = The British Journal of Surgery | volume = 98 | issue = 11 | pages = 1556–1560 | date = November 2011 | pmid = 21706476 | doi = 10.1002/bjs.7595 | s2cid = 20149393 }}</ref> Characterised as intimal hyperplasia and medial granulomatous inflammation with elastic lamina fragmentation with a CD4+ predominant T cell infiltrate, currently biopsy is only considered confirmatory for the clinical diagnosis, or one of the diagnostic criteria.<ref name="pmid21176820"/>