SAT0410 Diagnostic mimicry of large vessel vasculitis/giant cell arteriitis (GCA)
Authors: O. Sander, S. Vordenbaeumen, B. Ostendorf, G. Chehab, J. Richter, R. Fischer-Betz, M. Schneider
Journal: Annals of the Rheumatic Diseases (2013)

<h3>Background</h3> GCA is a vasculitis affecting arteria temporalis and other large vessels resulting in occlusion of larger arteries or aortal aneurysma. Clinical presentation varies from final organ damage (e.g. amaurosis), claudicatio, polymyalgic pain and weight loss to elevated acute phase reactants without other clinical symptoms. Non invasive imaging procedures like ultrasound (US), Magnetic resonance imaging (MRI) and positron emission tomography (PET) have replaced the former diagnostic gold standard, biopsy. <h3>Objectives</h3> This descriptive study is a collection of diseases mimicking GCA. <h3>Methods</h3> All patients attending our clinic and ambulance with unexplained elevation of acute phase reactants, polymyalgic pain, pulseless extremities, claudication and/or a new onset of temporal pain were screened for a large vessel vasculitis. Clinical investigation, serological tests, B-mode and Doppler sonography of the temporal, carotidal, subclavian, axillar, brachial and femoral arteries as well as the abdominal aorta were performed in all patients. Wherever the typical anamnestic, clinical, serological and ultrasound pattern of GCA or other obvious explanations for the disease were not evident, an extended work up with MRI, PET and/or a biopsy was performed. <h3>Results</h3> In our selected cohort 810 screening and 279 follow up US investigations were performed. The most frequent results were "normal" (n=236), arteriosclerosis (n=283), and typical segmental vasculitis (GCA, n=264). GCA could be confirmed by regression of vessel inflammation in follow up investigations under steroid therapy in most cases. A GCA like US pattern was documented also in 12 patients with a preexisting other rheumatic disease (Rheumatoid arthritis n=1, Spondylitis ankylosans n=4, Crohns disease n=1, ulcerative colitis n=1, psoriatic arthritis n=2, panarteriitis nodosa n=2, Erdheim-Chester Disease n=1). The 2 patients with panarteriitis disease had additional affection of distal mesenterial arteries, lower limb or mesenterial aneurisms and clinical features of panarteriitis. 3 patients with ANCA associated vasculitis had an affection of the temporal artery and one of the carotid arteries. 6 patients had a panarteriitis and 1 patient had SLE affecting other large vessels but not the upper aortal branches. 3 patients had a dissection of the aorta, affecting the branches, too. 1 patient had a stromal tumor of the temporal artery, one patient had Kimura's disease with bilateral affection of the temporal arteries and one patient had a Tanger syndrome affecting all large vessels. All those 17 patients showed different patterns in US. <h3>Conclusions</h3> 3.3% of the patients, screened for GCA and 9.3% of those with non-arteriosclerotic lesions in US did not have classical GCA. Extended screening ultrasonography is able to detect GCA, GCA like vasculitis in chronic inflammatory diseases but also rare conditions like other vasculitis, metabolic diseases or tumors. Those patients often have a higher variety in age, a longer clinical course, other clinical symptoms, or don't have that typical symmetrical segmental and circular vessel inflammation. <h3>Disclosure of Interest</h3> None Declared