The occurrence of intrathoracic new growths has been known for a great many years, but their recognition during life has been rare until comparatively recent years. The rapid advancement made in methods of thoracic diagnosis, especially since the use of the roentgen ray, has led to the early diagnosis of intrathoracic tumors and to the application of various types of treatment for the relief from symptoms. Roentgen rays and radium are probably the most commonly used agents in conservative treatment. In some of the cases of malignant tumors, such as the different types of malignant lymphomas and some of the sarcomas, there has been marked improvement. The lack of response of many of the tumors to the more conservative methods of treatment has stimulated surgical intervention with the view of radical removal of the diseased tissue. I have previously reported five cases of intrathoracic tumors which were removed by transpleural