Abstract
A roentgenographically occult lung cancer of the right lower lobe bronchus was diagnosed bronchoscopically in a 57-year-old man. Although intraluminal radiotherapy had been planned first, he actually received right lower lobectomy with lymph node dissection. The detection of a small nodule suspected to be metastasis in the right S^6 area by chest CT was the reason for the operation. The lesion in right B^<9+10> extended longitudinally was 25mm and was intramural poorly differentiated squamous cell carcinoma. The pathology of the right S^6 lesion in the same lower lobe was also poorly differentiated squamous cell carcinoma with severe atypism. Squamous cell carcinoma within the bronchial wall extending for more than 20mm of longitudinal extention is sometimes metastatic via the lymphatics. Although this peripheral lung lesion was suspected to be multiple lung cancer, it was diagnosed as intrapulmonary metastasis for the above reason. It is necessary to examine the entire body for the existence of metastasis or multiple lesions even in the cases of lung cancer limited to within the bronchial wall.
