{
  "abstract": "A woman in her 40s presented with a gradually enlarging swelling and pain in the left neck for 10 days. She had been taking a low-dose oral contraceptive containing 1 mg of norethisterone and 0.035 mg of ethinylestradiol for 3 months to treat iron deficiency anaemia caused by multiple uterine fibroids. Her vital signs were as follows: temperature 36.4°C, heart rate 134 bpm, blood pressure 177/112 mm Hg, respiratory rate 13 breaths/min and oxygen saturation 100% on room air. Physical examination revealed a mobile, firm, elastic, tender mass approximately 5 cm in size in the left neck. Laboratory tests showed an elevated D-dimer level of 1.9 µg/mL. Contrast-enhanced CT revealed a filling defect extending from the left common jugular vein to the left internal and external jugular veins, along with thickening of the left common jugular vein wall and increased fat attenuation surrounding the vein ( figure 1). Additionally, a filling defect was observed in the right lower pulmonary artery (figure 2). Based on these findings, the patient was diagnosed with upper extremity deep venous thrombosis (UEDVT) and pulmonary thromboembolism (PTE) induced by oral contraceptive use, and rivaroxaban therapy was initiated. Additional tests for coagulation disorders (protein C activity, protein S and antithrombin III activity) and autoimmune diseases (antinuclear antibody, lupus anticoagulant) revealed no abnormalities. Evaluation for the malignancy was not performed due to the absence of a significant family history or symptoms and the patient’s relatively young age. To assess the therapeutic response and confirm resolution of thrombosis and pulmonary embolism, a follow-up contrast-enhanced CT was obtained on day 8. It showed improvement in the thrombus of the left common jugular, internal jugular and external jugular veins, as well as the disappearance of the pulmonary artery thrombus. The patient was discharged on day 9. A follow-up CT performed 3 months after discharge revealed complete resolution of the cervical thrombus; therefore, anticoagulant therapy was discontinued.",
  "authors": [
    {
      "affiliations": [
        "Department of General Internal Medicine, St Marianna University School of Medicine, Kawasaki, Kanagawa Prefecture, Japan",
        "Department of General Internal Medicine, Kawasaki Municipal Tama Hospital, Kawasaki, Kanagawa Prefecture, Japan"
      ],
      "name": "Kasane Ikegami"
    },
    {
      "affiliations": [
        "Department of General Internal Medicine, St Marianna University School of Medicine, Kawasaki, Kanagawa Prefecture, Japan",
        "Department of General Internal Medicine, Kawasaki Municipal Tama Hospital, Kawasaki, Kanagawa Prefecture, Japan"
      ],
      "name": "Takuya Otsuki"
    },
    {
      "affiliations": [
        "Division of Cardiology, Department of Internal Medicine, St Marianna University School of Medicine, Kawasaki, Kanagawa Prefecture, Japan",
        "Division of Cardiology, Department of Internal Medicine, Kawasaki Municipal Tama Hospital, Kawasaki, Kanagawa Prefecture, Japan"
      ],
      "name": "Nozomi Kotoku"
    },
    {
      "affiliations": [
        "Department of General Medicine, Yokohama City University School of Medicine Graduate School of Medicine, Yokohama, Japan"
      ],
      "name": "Kosuke Ishizuka"
    }
  ],
  "title": "Upper extremity deep venous thrombosis that developed after starting low-dose oral contraceptive",
  "uid": "8e752dc3-5e32-5712-8081-89ce511d0521"
}