Temporal artery biopsy in the diagnosis of giant cell arteritis: Bigger is not always better

Accurate early giant cell arteritis (GCA) diagnosis can be established through temporal artery biopsy (TAB). We herein investigate the relationship between specimen length and positive TAB result in a tertiary-care hospital in Germany during a 8-year period. Secondarily, we studied the relationships of specific epidemiological and laboratory parameters with positive TABs. We retrospectively reviewed the medical records of all patients with suspected GCA, who underwent TAB in our institution. The total sample consisted of 116 patients with a mean age of 76.1 (SD 7.7) years. Mean specimen length post-fixation was 0.94 cm (SD 0.49). The TAB(+) group consisted of 64 patients (55.2%). The specimen length was comparable in the two groups (0.96 cm vs 0.91 cm, p = 0.581). Twenty six TAB(+) patients (41%) had a post-fixation specimen longer than 1 cm, comparable with the respective percentage in the TAB(−) group (42%, p = 1). All laboratory tests performed were statistically significantly different in the two groups. We conclude that TAB length is not associated with the TAB diagnostic yield in patients with clinical suspicion of GCA. •All laboratory tests performed (i.e. ESR after the first hour, CRP, platelet count) were statistically significantly different between the TAB(+) and TAB(−) groups.•Specimen length was comparable in the two groups (0.96 cm vs 0.91 cm, p = 0.581). In other words, TAB length was not associated with the TAB diagnostic yield in patients with clinical suspicion of GCA.•Logistic regression indicated that a five-variable model, consisting of age, specimen length post-fixation, ESR after the first hour, CRP and platelet count, can predict outcome in 70% of cases (compared to 55.2% in the null model).•Only platelet count was statistically significant in multivariate logistic regression.