Abstract
This report describes a rare case of extensive aortitis associated with granulocyte colony-stimulating factor (G-CSF) administration in a 74-year-old male with castration-resistant prostate cancer and multiple metastases. The patient developed recurrent fever and elevated inflammatory markers after receiving filgrastim for docetaxel-induced neutropenia. Despite antibiotic treatment, his fever persisted. A contrast-enhanced CT scan revealed circumferential wall thickening of the common carotid artery to the aortic arch and abdominal aorta, prompting suspicion of G-CSF-associated vasculitis. Following the initiation of prednisolone, the patient's fever resolved, inflammatory markers decreased, and clinical status improved. Subsequent CT scans showed a reduction in aortic wall thickening. This case highlighted that G-CSF-associated vasculitis can occur in older male cancer patients, urging clinicians to consider aortitis in the differential diagnosis for unexplained fever and inflammation following G-CSF administration and promptly perform contrast-enhanced CT when suspected.