DIFFUSE, extensive, bilateral pulmonary lesions producing minimal symptoms and frequently found on routine roentgen examination present a challenging diagnostic problem. They may represent a fibrotic reaction to inhalation or radiation trauma or to infection, both bacterial and fungus; a primary pulmonary neoplasm, or metastatic lesions from asymptomatic primary carcinoma elsewhere. A presumptive diagnosis can occasionally be made on the basis of the history; examination of bronchial fluid, blood and bone marrow; sensitivity studies, or biopsy of peripheral lymph nodes. An absolute diagnosis, however, cannot be made in a large number of patients by these indirect methods. In a series of 50 patients we have been able to diagnose such lesions with certainty by the use of a simple technic of pulmonary biopsy, which in our experience has led to no serious complications and has been of minimal discomfort to the patients.
SURGICAL TECHNIC
In the first 12 cases in which