摘要:Introduction: Spontaneous and isolated internal jugular vein (IJV) thrombosis is a rare entity, and atypical localization for venous thromboembolism usually occurs after an oropharyngeal infection, cancer, central venous catheter, and ovarian hyperstimulation syndrome. This report describes a case of spontaneous IJV thrombosis leading to neck pain and swelling as a primary manifestation of antiphospholipid (Hughes) syndrome. Case presentation: A 44-year-old male with no significant past medical history presented with a 1-week duration of right-sided painful neck swelling. Duplex ultrasound and computed tomography angiogram revealed right IJV thrombosis. Hematology studies were normal apart from positive lupus anticoagulant. The patient was managed conservatively with low molecular weight heparin, antibiotics, and close follow-up. Conclusion: Acute spontaneous IJV thrombosis as a primary presentation of antiphospholipid syndrome is extremely uncommon. We should be aware of the possibility of this condition in the differential diagnosis and management, as long-term anticoagulation is needed.