Internal Jugular Vein Thrombosis as the Initial Presentation of Antiphospholipid Antibody-positive Vascular Behçet Disease: A Clinical Image.

Internal jugular vein (IJV) thrombosis is a rare and potentially life-threatening condition commonly caused by central venous catheter insertion, malignant tumors, and neck infections. A 45-year-old woman with an unremarkable medical history presented with left neck pain. Imaging studies of a suspected mediastinal tumor revealed IJV thrombosis. No malignancy was identified by imaging or upper gastrointestinal endoscopy. Despite suspicion of antiphospholipid antibody syndrome (APS) and treatment with warfarin, subsequent testing did not provide conclusive evidence for a definitive diagnosis of APS. Later, genital ulcers, right scleritis, folliculitis-like lesions on the trunk and femor, and hand arthritis developed. Based on her clinical findings and positive human leukocyte antigen A26, the patient was diagnosed with vascular Behçet disease one year after the initial presentation. While IJV is rare, its differential diagnosis is diverse. This includes uncommon causes, such as deep venous thrombosis secondary to vascular Behçet disease.