A 70 aged man with a habit of heavy smoking underwent the left upper lobectomy under the diagnosis histologial examination on the main tumor situated in periphery of S1+2 showed undifferentiated adenocarcinoma. Following the histological examination on the epithelium of B1+2b, early invasive cancer (epidermoid carcinoma) was found. Detailed examintions were made histologically on the epithelium in the vicinity of early cancer with special reference to the histgenesis of lung cancer.
