retrospectively , operative findings were compared with the results of clinicoroentgenological , bronchological studies and mediastinoscopy , the most frequent causes of uneffective interventions were as follows : massive metastatic involvement of lymph nodes of the lung hilus and mediastinum ( in 26 patients ) and perivasal tumor dissemination ( in 18 patients ) .
C0025065
mediastinoscopy
C0025066
mediastinum