Abstract
According to the hypothesis of multi-step carcinogenesis, we believe that squamous cell carcinoma appears in bronchial epithelium through the precancerous lesion (squamous metaplasia and dysplasia). We cannot distinguish in-situ carcinoma from dysplasia without a skillful diagnosis by experienced pathologists. However, such a pathological diagnosis is a universal criterion, isn't it? Recently, it is recommended that a small-sized bronchioloal-veolar carcinoma in the peripheral lung is enough for follow-up examinations, even though its lesion is recognized as a cancerous lesion. When we evaluate the necessity of therapeutic treatments of the intrabronchial lesion, we should regard the biological characteristics as important. We attempted to evaluate the biological characteristics of the intrabronchial lesions using cell proliferation, mutant p53 protein expression and the deficiency of cell to cell adhesion ability, and we concluded that these changes initially occurred in the neighborhood of the basement membrane. (JJSRE. 2006;28:601-606)
