Pronunciation: (MEE-dee-uh-STY-noh-skope)

A thin, tube-like instrument used to examine the tissues and lymph nodes in the area between the lungs. These tissues include the heart and its large blood vessels, trachea, esophagus, and bronchi. The mediastinoscope has a light and a lens for viewing and may also have a tool to remove tissue. It is inserted into the chest through a cut above the breastbone.

Source: NCI Dictionary of Cancer Terms

Caption: Mediastinoscopy. A mediastinoscope is inserted into the chest through an incision above the breastbone to look for abnormal areas between the lungs. A mediastinoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a cutting tool. Tissue samples may be taken from lymph nodes on the right side of the chest and checked under a microscope for signs of cancer. In an anterior mediastinotomy (Chamberlain procedure), the incision is made beside the breastbone to remove tissue samples from the lymph nodes on the left side of the chest.