Lung Metastases-Endobronchial

(see also Obstructive Lung Disease, [[Obstructive Lung Disease]])

Etiology

  • Breast Cancer (see Breast Cancer, [[Breast Cancer]]))
    • Most common tumor to metastasize to the airway (accounts in 36% of endobronchial mets, by autopsy studies)
    • Occurs more commonly in post-menopausal cases
    • May occur up to 33 years later
    • Rarely, breast cancer may also directly invade trachea from mediastinal mets
  • Cervical Cancer (see Cervical Cancer, [[Cervical Cancer]])
    • Common etiology of endobronchial metastases
  • Chronic Lymphocytic Leukemia (CLL) (see Chronic Lymphocytic Leukemia, [[Chronic Lymphocytic Leukemia]])
    • May occur late in course
    • May rarely infiltrate bronchial mucosa
  • Colon Cancer (see Colon Cancer, [[Colon Cancer]])
    • Common etiology of endobronchial metastases
  • Endometrioma (see Endometrioma, [[Endometrioma]])
  • Esophageal Cancer (see Esophageal Cancer, [[Esophageal Cancer]])
    • May directly invade trachea (usually at level of left mainstem bronchus)
  • Germ Cell Tumor (see Germ Cell Tumor, [[Germ Cell Tumor]])
  • Head and Neck Cancer (see Head and Neck Cancer, [[Head and Neck Cancer]])
  • Hodgkin’s Disease (see Hodgkins Disease, [[Hodgkins Disease]])
    • May involve airway by direct extension from hilar/peribronchial nodes or may seed airway via hematogenous or lymphatic spread
  • Kaposi Sacoma (see Kaposi Sarcoma, [[Kaposi Sarcoma]])
    • Associated with Human Immunodeficiency Virus (HIV) infection
    • Involves lungs in 33-50% of cases
  • Lymphoma (see Lymphoma, [[Lymphoma]])
    • May involve airway by direct extension from hilar/peribronchial nodes or may seed airway via hematogenous or lymphatic spread
  • Melanoma (see Melanoma, [[Melanoma]])
    • Common etiology of endobronchial metastases
  • Ovarian Cancer (see Ovarian Cancer, [[Ovarian Cancer]])
  • Plasmacytoma (see Multiple Myeloma, [[Multiple Myeloma]])
  • Renal Cell Cancer (see Renal Cancer, [[Renal Cancer]])
    • Common etiology of endobronchial metastases
  • Testicular Cancer (see Testicular Cancer, [[Testicular Cancer]])
    • Uncommon etiology of endobronchial metastases
  • Thyroid Cancer (see Thyroid Cancer, [[Thyroid Cancer]])
    • May directly invade lower larynx/ trachea or metastasize to trachea
  • Urothelial Cell Carcinoma (Transitional Cell Carcinoma) (see Urothelial Cell Carcinoma, [[Urothelial Cell Carcinoma]])

Physiology

  • Hematogenously Spread Malgnancies: may metastasize to airway (but this rarely occurs in absence of parenchymal lung metastases)

Diagnosis

  • Inspiratory CXR: may reveal underinflation
  • Expiratory CXR: may reveal air trapping in affected lung
  • V/Q: may reveal decreased or absent ventilation and decreased perfusion to affected side
  • FOB (diagnostic procedure of choice): endobronchial tumor
    • EBB: may be hazardous in KS due to risk of hemorrhage
  • CXR/Chest CT: may reveal atelectasis or post-obstructive pneumonia
    • In infants, pores of Kohn are poorly developed (hence, obstruction is more likely to produce distal atelectasis)
    • Presence of air bronchogram: suggests only partial obstruction
    • Inspiratory (lung will expand normally) vs. expiratory (lung will not deflate normally) films may revel partial obstruction (also, mediastinum will shift away from affected side on expiration
  • HRCT: may reveal endobronchial lesions in some cases

Clinical Manifestations

Pulmonary Manifestations

  • Hemoptysis (see Hemoptysis, [[Hemoptysis]])
    • Rare in Kaposi Sarcoma
  • Inspiratory “Bagpipe” Sign: prolonged inspiratory time on the affected side
  • Localize Expiratory Wheeze: over the site of obstruction
  • Symptoms/Signs of Airway Obstruction
    • Rare in Kaposi Sarcoma

Treatment

  • Thyroid Cancer (with Direct Invasion): may be resected with tracheal reconstruction
  • Other Tumors: may be managed with laser/stenting

References

  • xxx