UNTIL recent years the mediastinum was considered as a “No Man’s Land” insofar as elective surgery was concerned. Except for the extirpation of the substernal goiters from the superior mediastinum, little else was attempted in this region. The collection of mediastinal tumors was left almost entirely to the pathologist as most of these entities were discovered at postmortem examination. As roentgen examination of the chest increased in popularity, however, the tumors were detected more frequently during life and the opportunity for clinical study became a frequent occurrence. With the development of improved surgical technics in the past decade, the third phase of study and treatment of mediastinal tumors has come into being. Early detection by roentgenography and early exploration of the mediastinum have combined to improve the clinical management and the prognosis of the patient with mediastinal neoplasm. The low morbidity and mortality of exploratory thoracotomy make this operation a safe method of diagnosis and treatment. Prolonged clinical observation is no longer a justifiable procedure in the management of these patients.
“The mediastinum is the space left in the median line of the chest by the non-approximation of the two pleurae (Gray’s Anatomy).” Classically, this space is subdivided into four compartments, all of which are surgically accessible (fig. 1). An imaginary plane extending anteriorly from the fourth thoracic vertebra to the articulation between the manubrium and the sternum forms the lower border of the superior mediastinum. This corresponds roughly with upper limits of the pericardium. Below this plane and above. . .