ABSTRACT
A1 E The anterior mediastinum (Zone 1) is bounded by the posterior surface of the sternum, the thoracic inlet, and the anterior surface of the great vessels, heart and pericardium. The middle mediastinum (Zone 2) extends to the anterior border
of the vertebrae. The posterior mediastinum (Zone 3) is the area posterior to the anterior border of the vertebrae. A thorough understanding of the anatomy and embryology of the mediastinum is important for the surgeon when evaluating, planning, diagnosing and operating on patients. Conditions that can present within Zone 1 include teratoma, thymic hyperplasia, thymic cysts, non-Hodgkin’s lymphoma, Hodgkin’s lymphoma and lymphangioma. In Zone 2, non-Hodgkin’s lymphoma, Hodgkin’s lymphoma, lymphangioma and foregut cysts and duplications can be seen. Similarly the conditions that can develop within Zone 3 include ganglioneuroma and neuroblastoma.
