Carcinoma in situ from the view of complete resection.

World Health Organisation (WHO) defined three types of preinvasive epithelial lesions, one of which is preinvasive bronchial squamous lesions consisting of dysplasia and carcinoma in situ (CIS). It is not clear whether or not CIS at the bronchial resection margin is to be considered as incomplete resection in the literature. Follow-up data of such patients using autofluorescence bronchoscopy proved that CIS regresses without further treatment in significant number of patients. It is therefore reasonable to accept any reported CIS lesion on frozen-section examination as complete clearance of the tumor and thus further resection may not be warranted.