BECAUSE of the many clinical and roentgenologic similarities of bronchiogenic carcinoma and pulmonary tuberculosis, their differentiation may present certain diagnostic difficulties. Among examination. An approximately equal number of cases were seen in the Diagnostic Clinic of the hospital, and the majority were referred for consultation with a thoracic surgeon. Since these patients Overholt's1 cases of primary cancer of the lung, there were 40 patients who were treated for pulmonary tuberculosis because of an originally erroneous diagnosis. Similarly, Moersch and Tinney2 reported that in their series of 448 patients with proved bronchiogenic carcinoma, 13 spent several months in tuberculosis sanatoriums before . . .