Generalized Giant Cell Arteritis Discovered on Positron Emission Tomography

An eighty two year old man with a remote history of metastatic melanoma status post chemotherapy presented with fatigue, generalized weakness, low grade fevers, abdominal pain and weight loss. Positron emission tomography (PET) scan was obtained, which revealed diffuse and symmetric increased F-18 Fluorodeoxyglucose (FDG) uptake throughout the large arterial vasculature in the neck, chest, abdomen, pelvis and lower extremities. CT angiogram showed subtle wall thickening involving the bilateral vertebral, bilateral axillary, left subclavian, abdominal aorta, bilateral common iliac, internal iliac, common femoral, superficial femoral, popliteal and anterior tibial arteries, consistent with large vessel vasculitis. Subsequent left temporal artery biopsy revealed multiple giant cells with associated lymphoid cells infiltrating all levels of the artery, but most focused in the media and adventitia, consistent with giant cell arteritis (GCA). The patient was started on prednisone, resulting in prompt improvement in his constitutional symptoms and normalization of his sedimentation rate.