Temporal artery involvement in AL amyloidosis: an important differential diagnosis for giant cell arteritis. A case report and literature review

Cranial giant cell arteritis mimickers: A masquerade to unveil

Giant cell arteritis (GCA) is a large-vessel vasculitis that affects cranial and extra-cranial arteries. Extra-cranial GCA presents mainly with non-specific symptoms and the differential diagnosis is very broad, while the cranial form has more typical clinical picture and physicians have a lower threshold for diagnosis and treatment. Although temporal artery biopsy (TAB) has an established role, ultrasound (US) is being increasingly used as the first-line imaging modality in suspected GCA. Vasculitides (especially ANCA-associated), hematological disorders (mainly amyloidosis), neoplasms, infections, atherosclerosis and local disorders can affect the temporal arteries or might mimic the symptoms of cranial GCA and produce US and TAB findings that resemble those of temporal vasculitis. Given that prompt diagnosis is essential and proper treatment varies significantly among these diseases, in this review we aimed to collectively present disorders that can masquerade cranial GCA.

Giant cell arteritis with spontaneous remission

The case of a 75-year-old woman diagnosed with polymyalgia rheumatica (PMR), treated with low doses of prednisone, and with clinical and analytical remission is reported. Two years later, she presented with a clinical picture of giant cell arteritis (GCA), including headache, diplopia, jaw pain, feeling of swelling in both temples, and elevation of acute phase reactants. Symptoms spontaneously subsided 2 weeks later, while analytical parameters improved without any treatment. A high-resolution colour Doppler ultrasound showed thickening of the intima-media complex with 'halo' sign in the right temporal artery. A biopsy of the right temporal artery was performed, although it was not successful, as no artery could be found, and the procedure became more complicated with an eyebrow ptosis due to a lesion in the frontal branch of the facial nerve. GCA diagnosis was based on the clinical, laboratory, and ultrasound findings. The patient was treated with prednisone and methotrexate, without clinical or analytical relapse. Comments are presented on the described cases of GCA with spontaneous remission, and the most appropriate treatments in these cases are discussed. Other peculiarities of the case, such as the progression to GCA more than 2 years after the onset of PMR, and the complications from the temporal artery biopsy are also mentioned.