A 68-year-old man with newly diagnosed gastric cancer presents with acute-onset bilateral lower extremity pain and swelling. Vital signs show BP 138/82, HR 92, RR 18, temp 37.2°C, SpO2 98% on room air. Examination reveals bilateral calf erythema and tenderness. D-dimer is markedly elevated at 8.5 μg/mL; compression ultrasound confirms bilateral DVTs. He denies recent immobilization, surgery, or trauma. Platelet count is normal. Which of the following best explains the underlying mechanism for these thrombotic complications?
- A)Surgical manipulation increasing endothelial damage
- B)Protein C resistance from factor V Leiden
- C)Immobilization causing venous stasis
- D)Cancer-induced tissue factor expression activating the extrinsic coagulation pathwayGABARITO
- E)Antithrombin deficiency from hepatic dysfunction
Explicação
Malignancy, especially adenocarcinomas like gastric cancer, activate coagulation through tissue factor (TF) expression on cancer cells and monocytes, initiating the extrinsic pathway and causing hypercoagulability with thromboembolism. Ver explicação completa e trilha adaptativa →