Clinical Images: Rapidly progressive granulocyte colony‐stimulating factor–associated arteritis: initial normal imaging as a diagnostic pitfall

The patient, a 53-year-old Japanese woman, presented to our hospital with fever and right neck pain. She had a history of breast carcinoma and had undergone chemotherapy with sacituzumab govitecan, which required pegfilgrastim. Seven days after the last pegfilgrastim dose, she developed generalized fatigue, fever, and right-sided neck pain (day 7). Contrast-enhanced computed tomography (CE-CT) did not reveal the origin of the fever on day 10 (A). Follow-up CE-CT on day 14 showed arterial wall thickening, especially in the right common carotid artery (B). Laboratory examinations revealed elevated serum C-reactive protein levels (26.68 mg/dL; normal range: below 0.14 mg/dL). Carotid ultrasonography showed thickening of the outer lines around the bifurcation of the right common carotid artery into the external and internal carotid arteries, strongly suggestive of arteritis (C). The patient was diagnosed with granulocyte colony-stimulating factor (G-CSF)–associated arteritis. Subsequently, prednisolone (initial dose: 1 mg/kg/day) was administered on day 14, which immediately improved her symptoms. Carotid ultrasonography repeated on day 18 showed an improvement in the wall thickening of the right common carotid artery (D). G-CSF–associated arteritis improves rapidly upon the discontinuation of G-CSF formulations or initiation of glucocorticoid therapy.1 Regarding the onset of arteritis, G-CSF–associated arteritis tends to present within 10 days of pegfilgrastim administration.2, 3 However, the onset pattern of arteritis remains unclear. Our case highlights the importance of frequent follow-up examinations when G-CSF–associated arteritis is suspected, even if initial tests show no abnormalities. Disclosure Statement. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.