Mesothelioma (summary)

This is a basic article for medical students and other non-radiologists.

Pleural mesotheliomas are malignant tumors of the lining of the lungs. There is a strong association with asbestos exposure.

Reference article

This is a summary article; read more in our article on mesothelioma.

Summary

  • epidemiology
    • relatively rare thoracic malignancy
    • majority of cases are related to asbestos exposure
      • occupational exposure from mining, construction, industrial work, etc.
    • more common in men
    • no association with smoking
  • presentation
    • progressive dyspnea
    • weight loss
    • chest wall pain (non-pleuritic)
    • examination findings
      • clubbing
      • pleural effusion (dull to percussion, quiet breath sounds)
  • pathogenesis
    • mesothelium is an epithelial serous lining of body cavities
    • asbestos fibers deposited in the lung may be carried to the pleura
      • cells undergo malignant change
    • latent period of 25-50 years from asbestos exposure to symptoms
    • peritoneal and pericardial mesothelioma are rare but may also occur
  • investigation
    • history of asbestos exposure
    • imaging
    • lung function tests
    • pleurocentesis
    • biopsy
  • treatment
    • limited role for radiotherapy and surgery
    • palliative chemotherapy
    • poor prognosis
      • median survival from diagnosis 8-14 months

Radiographic features

Plain radiograph

Chest x-ray is often non-specific though it may show a pleural opacity. Depending on the location and size this may be a small opacification in the lateral aspect or it may extend to encase the whole hemithorax. This produces a 'white-out' appearance with the trachea remaining central or shifting towards the side of the lesion. Pleural effusion is common and mediastinal lymphadenopathy may be seen.

CT

CT is used for the assessment and staging of mesothelioma. It appears as a nodular mass along the pleural surfaces which may be calcified. Direct invasion of tissues (e.g. chest wall, diaphragm) can be seen on CT and it may reveal metastases to the lymph nodes, contralateral lung or other organs.

See also

Medical student radiology curriculum