Tumor Embolism

Epidemiology

  • Most cases are associated with breast cancer, gastric cancer, or lung cancer

Etiology

  • Mucin-Producing Adenocarcinomas (occur mainly in cases with liver mets/ usually microscopic tumor emboli):
    • Breast Cancer: accounts for 67% of tumor emboli cases (Schriner, 1991)
    • Gastric Cancer (first case reported in 1897):
    • Colon Cancer:
  • Renal Cell Carcinoma (usually macroscopic -> emboli via IVC):
  • Hepatoma (usually macroscopic -> emboli via IVC): older literature suggests a high incidence with hepatoma
  • Choriocarcinoma (usually macroscopic -> emboli via IVC): trophoblastic tumor fragments may embolize during hysterectomy or during resection
  • Sarcoma (usually macroscopic -> emboli via IVC):
  • Atrial Myxoma:
  • Head Trauma: brain cells may be found in lung vasculature in some cases
  • Abdominal Trauma: liver cells may be found in lung vasculature in some cases
  • CPR: bone marrow may be found in lung vasculature in some cases
  • Lung Cancer:
  • Prostate Cancer:

Physiology

  • Occlusion of the microvasculature by metastatic tumor emboli

Diagnosis

  • ABG: hypoxemia
  • CXR/Chest CT Patterns
    • Lymphangitic pattern: seen in some cases (lymphangitic mets may be seen histologically, more than is evident on CXR)
      • Septal thickening
    • Normal CXR: present in most cases
  • CT Angio: usually does not show thrombi
  • V/Q Scan: usually abnormal with multiple peripheral subsegmental perfusion defects
    • May mimic PE
  • Pulm angio: usually normal (some cases have defects)
  • Swan: PA blood samplng in PCWP position may demonstrate tumor cells

Clinical Syndromes

  • Acute Lung Injury-ARDS (see [[Acute Lung Injury-ARDS]])
    • Due to massive microscopic emboli
    • Acute dyspnea:
  • Pulmonary Hypertension/Cor Pulmonale (see Pulmonary Hypertension, [[Pulmonary Hypertension]])
    • Classic pattern reported in tumor emboli
    • Dyspnea (common):
    • Cough (8-47% of cases):
    • Pleuritic chest pain (18-28% of cases):
    • Hemoptysis (5-18% of cases):
    • Signs of pulmonary HTN (only 15-20% of cases):

Treatment

  • Surgery: has been reported to be useful in cases with large tumor emboli from RCC or atrial myxoma
  • Chemo: useful for microscopic cases from breast cancer or choriocarcinoma

References

  • Pulmonary tumor embolism: a review of the literature. Am J Med 2003;115:228 –32.
  • [Pulmonary arterial hypertension due to tumor emboli]. Rev Mal Respir 2007;24:359–66.