A procedure that uses an endoscope (a thin, tube-like instrument with a light and lens) to examine or treat the organs in the mediastinum (the space between the lungs) and nearby lymph nodes.

Cells or tissue may be removed for examination under a microscope. Doctors often use mediastinoscopy to get a sample of tissue from the lymph nodes on the right side of the chest.

The type of endoscope used for this procedure is called a mediastinoscope.