Pegfilgrastim-induced vasculitis of the subclavian and basilar artery complicated by subarachnoid hemorrhage in a breast cancer patient: a case report and review of the literature

Background Pegfilgrastim (PEG) is a sustained-duration pegylated form of filgrastim, a granulocyte-colony stimulating factor agent that is widely used as prophylaxis against febrile neutropenia during chemotherapy. We report the case of a breast cancer patient who developed PEG-induced vasculitis complicated by subarachnoid hemorrhage (SAH) and review the relevant literature. Case presentation A 48-year-old woman had undergone surgery for breast cancer and was receiving docetaxel and cyclophosphamide as adjuvant chemotherapy (docetaxel 75 mg/m(2), cyclophosphamide 600 mg/m(2)); on day 4 of treatment, PEG had been administered. On day 14, she was admitted to hospital with fever, general malaise, and neck pain, and her C-reactive protein level was found to be high (12.65 mg/dL). Although infection was initially suspected, antimicrobial treatment was ineffective and other laboratory test results were negative for this. Contrast-enhanced computed tomography on day 22 showed thickened vessel walls in the left subclavian artery, the origin of the common carotid artery, and the thoracoabdominal aorta. On day 26, magnetic resonance imaging of the head to investigate possible causes of headache showed signs consistent with SAH, and magnetic resonance angiography images showed irregularity in the basilar artery wall; the findings of both studies were considered to be due to PEG-induced vasculitis. Once treatment with prednisolone 40 mg/day had started, the wall thickening and irregularity improved. Conclusion Although an uncommon adverse effect, vasculitis affecting vessels of various sizes may be caused by PEG. To the best of our knowledge, this report is the first to describe a case of G-CSF-induced vasculitis complicated by SAH. In cases of persistent high fever and elevated inflammatory response after PEG administration and in the absence of infection, clinicians should consider the possibility of drug-induced vasculitis.