Internal jugular vein thrombosis by protein C activated resistance

Introduction: Jugular vein thrombosis is mainly due to infectious, neoplastic and iatrogenic causes. Activated protein C (APC) resistance is an exceptional cause of jugular vein thrombosis. Case report: A 40-year-old woman consulted for left lateral neck swelling present for two weeks. Neck ultrasound revealed left internal jugular vein thrombosis, which was confirmed by contrast CT. The rest of the examination, including routine clotting assessment and inflammatory work-up, was normal. Further investigations demonstrated APC resistance with Factor V Leiden mutation. Treatment consisted of oral anticoagulants with a good outcome. Discussion: APC resistance is a recently identified and relatively frequent cause of thrombophilia, mostly due to Factor V Leiden mutation. APC resistance is responsible for 20% to 50% of all thrombotic events. The laboratory diagnosis is based on two tests: a phenotypic test based on APTT with and without APC and a genotypic test based on detection of a Factor V Leiden mutation. Conclusion: Screening for APC resistance and Factor V Leiden mutation is now part of the aetiological work-up of thromboses, particularly in subjects younger than 50. Treatment is based on oral anticoagulants. (C) 2011 Elsevier Masson SAS. All rights reserved.