Giant cell (Temporal) Arteritis
Classical giant-cell arteritis - Marked intimal thickening. Dense, sometimes granulomatous chronic inflammation, including lymphocytes, histiocytes and giant cells, often closely related to fragmented elastica.
Atypical giant-cell arteritis - Less dense chronic inflammation, occasional giant cells only. Moderate or marked intimal thickening, sometimes with dense medial fibrosis. Probably a stage in the resolution of classical giant-cell arteritis.
Healed arteritis - Irregular intimal thickening, intimal and medial fibrosis. Focal areas of persistent chronic inflammation.
Arteriosclerosis - Concentric intimal thickening with fragmentation and reduplication of the internal elastic laminlla. No inflammation. Very little medial fibrosis. Occasional focal areas of calcification.
Atherosclerosis - Irregular, sometimes marked intimal thickening with focal areas of intimal necrosis and medial fibrosis. Patchy adventitial lymphocytic infiltrates. No giant cells.
Normal histology - Progressive age related intimal thickening makes precise definition impossible. All arteries in this group had intimal thickness 100 µm and an intima:media thickness ratio < 0.25.
Allsop, CJ, Gallagher PJ: Temporal artery biopsy in giant-cell arteritis. A reapraisal. Am J Surg Pathol 5: 317-323 ; 1981
