RT - European Journal of Gynaecological Oncology ID - 10.22514/ejgo.2026.034 T1 - Eflapegrastim-induced large vessel vasculitis in patient treated with recurrent uterine leiomyosarcoma A1 - Enoch Hong A1 - Ja Young Kim A1 - Eujene Jung A1 - Uchul Ju K1 - Granulocyte-colony stimulating factor; Eflapegrastim; Large-vessel vasculitis; Workup YR - 2026 SP - 117 AB -

Background: Granulocyte colony-stimulating factor (G-CSF) is widely used to prevent febrile neutropenia during chemotherapy. However, it can rarely induce large-vessel vasculitis (LVV), a condition that is challenging to recognize early and may lead to serious complications. Case: A 66-year-old woman with recurrent uterine leiomyosarcoma received long-acting G-CSF (eflapegrastim) for prophylaxis against neutropenia after initial systemic chemotherapy. Ten days after the first administration of eflapegrastim, she developed fever and fatigue. Contrast-enhanced computed tomography (CT) revealed new circumferential wall thickening of the aortic arch, proximal descending thoracic aorta, left proximal common carotid artery, and proximal subclavian artery. Positron emission tomography (PET) subsequently demonstrated increased fluorodeoxyglucose uptake, supporting a diagnosis of acute vasculitis. Corticosteroid therapy was promptly initiated after multidisciplinary discussion, resulting in rapid symptomatic improvement within 2 weeks and complete radiologic resolution after 4 weeks. Conclusion: Acute LVV induced by long-acting G-CSF is an emerging adverse event with potentially life-threatening consequences. Early suspicion and prompt use of imaging modalities, such as CT and PET, are essential for accurate diagnosis, enabling timely corticosteroid therapy and improved clinical outcomes.