Inflammation limited to the adventitia, with inflammatory cells involving the adventitia more or less extensively, frequently in contact with the external elastic lamina but without obvious extension into the media.
From: Cavazza A, Muratore F, Boiardi L, et al. Inflamed temporal artery: Histologic findings in 354 biopsies, with clinical correlations. Am J Surg Pathol 2014; 38:1360. DOI:
10.1097/PAS.0000000000000244. Copyright © 2014. Reproduced with permission from Wolters Kluwer Health. Unauthorized reproduction of this material is prohibited.