The mediastinum is the space that separates the 2 lungs and contains the heart, thymus, esophagus, trachea, the large blood vessels, and lymph nodes. A mediastinoscopy is a procedure in which a lighted instrument (mediastinoscope) is inserted through a neck incision to visually examine the structures in the top of the chest cavity.

Most commonly this procedure is used to examine lymph nodes in a patient with lung cancer, for disease staging purposes. A sample (biopsy) may be taken with the mediastinoscope.

This procedure is done in the hospital. You will be given a general anesthesia. An endotracheal tube is inserted. An incision is made in the neck and the mediastinoscope is inserted through this incision into the mid-part of the chest. Tissue samples are taken, usually of the lymph nodes surrounding the airway. The scope is then withdrawn, and the incision is closed with stitches.

You must sign an informed consent form. You will not be able to have food or fluid for 8 hours before the test.

You will be unconscious during the procedure. There will be some tenderness at the site of the incision afterward. You may have a sore throat after the test.

This procedure is used in diagnosing a variety of diseases when other tests such as sputum cytology, lung scans, radiography, and bronchoscopic biopsies do not provide a diagnosis. It is also used to assist in the staging of lung cancer.

There are no abnormal lymph node tissues.

Abnormal findings may indicate lung cancer, tuberculosis, the spread of disease from one body part to another, sarcoidosis (a disease that causes nodules, usually affecting the lungs, lymphoma (abnormalities in the lymph tissues), and Hodgkin's disease.

There is a risk of puncture of the esophagus, trachea, or the blood vessels, which in some circumstances can lead to potentially fatal bleeding.