Lung is a common site for metastasis from malignancies from other organs.

• Lung is a capillary bed and the entire cardiac output passes through it, thus it is no surprise tumors get trapped in lungs.
• Various patterns of metastasis should be recognized. Common patterns are
  • Solitary
  • Cannon balls
  • Lymphangitic
  • Pleural effusions

Clinical Presentation

Mode of clinical presentation varies depending on the pattern of metastasis.

• Asymptomatic, detected on routine CXR.
• Cough, hemoptysis, pneumonia, wheezing with endobronchial mets.
• Shortness of breath, cough with lymphatic spread.
• Pleuritic pain, cough and shortness of breath with pleural effusions.

Diagnosis

Again depends on the metastatic pattern.

• FNAB for solitary or multiple lung mets.
• Sputum cytology and bronchoscopy for endobronchial mets.
• Pleural fluid cytology for effusions.
• Tranbronchial lung biopsy for lymphatic spread.

Treatment

Very important treatment issues revolve around the presence and pattern of metastasis.

• Lung metastasis most often would preclude a surgical curative resection of the primary.
• Surgical resection of a solitary lung metastasis along with resection of the primary can accomplish cure in certain tumors.
• Brachytherapy therapy may be useful to relieve symptoms with endobronchial mets.
• Pleural sclerosis is necessary in pleural effusions.
• Certain chemotherapeutic agents can sequester in effusions.