ABSTRACT
Information on the multistage development of lung cancer has been reviewed in several articles in 2000 describing the molecular alterations preceding histopathologic changes, preparing the way for new methods in the early detection of lung cancer.1,2 By using fluorescence bronchoscopy in smokers at high risk for lung cancer, unique lesions consisting of capillary loop vessels closely juxtaposed to and projecting into metaplastic or dysplastic squamous bronchial epithelium, angiogenic squamous dysplasia (ASD) has been described by Keith et al.3 The presence of this lesion in high-risk smokers suggests that aberrant patterns of microvascularization may occur at an early stage of bronchial carcinogenesis. Also multiple small clonal or subclonal patches containing molecular abnormalities are present in normal or slightly abnormal bronchial epithelium of patients with lung cancer.2
