False Negative and True Negative Reports of Temporal Artery Biopsies in Temporal Giant Cell Arteritis

Purpose: To investigate the role of multiple slide preparations in defining false from true negative temporal artery biopsies in cases of temporal giant cell arteritis.Methods: Paraffin embedded blocks of 100 randomly selected cases with clinical diagnosis of giant cell arteritis but negative histopathology in a 5-year period were retrieved completely and new slides were re-evaluated by light microscopy in terms of histopathology findings of giant cell arteritis. The demographic and analytic data were processed by SPSS version 22. Results: Among the total of 100 randomized cases, mean age was 62.75±12.8 years with 1.17 female to male ratio. The initial length of excised temporal artery was 15.39±7.56 mm. The mean number of initial slides/patient was 3.24±0.74 with mean of 2.93±0.2 sections/slide. The average of total initial sections/patient was 9.53±2.46 with 0.72±0.29 section/1 mm of artery. After retrieval, the mean number of slides/patient was 2.83±0.96 with mean of 2.84±0.39 sections/slide. The average of total secondary sections/patient was 8.12±3.09 with 0.63±0.39 sections/1 mm of artery. The average of total prepared sections per each specimen was 17.66±4.43. Among theretrieved specimens, only one case (1%) showed the histopathological findings of giant cell arteritis. Conclusion: Despite the presence of skip lesions in histopathology of temporal giant cell arteritis, increasing the levels of routine sections does not increase the diagnostic yield of the histopathology.