Mediastinal Masses - Indirect Findings

These are set of physical findings due to compression or disruption of structures in the mediastinum. Unlike direct findings secondary to mass, these findings are easy to recognize. There are lot of important structures in the mediastinum.

Focused Exam

Nerves:

• Recurrent laryngeal nerve injury results in hoarseness of voice and the cough is ineffective (bovine cough). The voice becomes hoarse. Left recurrent laryngeal nerve courses through the mediastinum while the right recurrent laryngeal nerve is located in neck. Hence intrathoracic lesions involve only left recurrent laryngeal nerve and the pathology is usually in aorta-pulmonary window.

• Sympathetic Chain
  Horner's syndrome can result from injury to sympathetic chain. Sympathetic chain is located in the posterior mediastinum in para vertebral location and thus pathology has to be in posterior mediastinum. The manifestations of the syndrome are ipsilateral miosis, partial ptosis, anhidrosis and enophthalmos.
• Phrenic Nerve
  Initially you get hiccough followed by paralysis of ipsilateral hemidiaphragm. Patients develop orthopnoea. Ipsilateral paradoxical movement of diaphragmatic motion can be recognized. Pathology is in the middle mediastinum.
• Intercostal Nerve
  Disruption can be recognized by focal bulging of intercostal space. Patient may have root pains along the thoracic dermatomes. Pathology is in paravertebral space of posterior mediastinum.

Vessels:

• SVC
  Obstruction to superior vena cava and its physical findings is described in a separate lesson.
• Aorta
  Disruption of function of aorta occurs rarely with mediastinal tumors.
• Pulmonary Artery
  Malignant lesions can invade pulmonary artery and occlude them. The tumor can erode into the pulmonary artery with resultant exsanguinating hemorrhage and death.
• Pulmonary Vein
  Pulmonary vein occlusion could result in pulmonary edema.
• Thoracic Duct
  Disruption results in chylothorax.

Tubes:

• Esophagus
  Dysphagia can result from obstruction to esophagus. Tracheoesophageal fistula can form and lead to aspiration pneumonia.
• Tracheo Bronchial Tree
  Obstruction gives rise to shortness of breath and wheezing.

Bones:

• Sternum
  Erosion of sternum results in pain and tenderness.
• Vertebra:
  Erosion of vertebra results in back pain. In extreme cases paraplegia can result from compression of spinal cord.