ENDOSCOPIC CRITERIA OF EARLY SQUAMOUS-CELL CARCINOMA OF THE BRONCHUS

Background. Early lung cancer, not extending beyond the bronchial cart ilaginous layer without regional lymph node involvement is considered curable by endoscopic laser therapy or limited surgery. The endoscopic criteria for early squamous cell carcinoma of the bronchus, however, have not yet been determined. Methods. For 44 resected lesions of roen tgenographically occult bronchogenic squamous cell carcinomas, the rel ationship between endoscopic findings and the degree of histologic ext ent of tumor was examined. Results. The lesions were divided into thre e types: polypoid or nodular (PN), flatly spreading (FS), and mixed. T hirty-three lesions arising from the central bronchus included 7, 19, and 7 of the PN, FS, and mixed types, respectively. In the central les ions, the degree of transmural invasion and the greatest dimension cor related, but the degree of intramural invasion of PN-type lesions was higher than that of the FS type. The PN-type lesions smaller than 10 m m and the FS type smaller than 15 mm in greatest dimension were found within the cartilaginous layer without regional lymph node involvement , All lesions of the mixed type were larger than 20 mm. Three of the l esions larger than 20 mm had regional lymph node involvement. All 11 l esions originating in the peripheral bronchus were of the FS type, and a lesion of only 5 mm in greatest dimension had extracartilaginous in vasion. Conclusions. The endoscopic criteria of early squamous cell ca rcinoma of the bronchus may be applied to central PN lesions smaller t han 10 mm and central FS lesions less than 15 mm in greatest dimension . Any lesions of mixed type should be excluded from the criteria.