SQUAMOUS METAPLASIA IN THE RESPIRATORY TRACT

This thesis discusses squamous cell metaplasia as a preneoplastic change in bronchial epithelium that occurs in response to toxic exposures, especially from cigarette smoke. The process of epithelial change from multi-row ciliated columnar to multilayered squamous epithelium and the associated consequences, such as chronic bronchitis and risk of lung cancer, especially in smokers, are described. The text also emphasizes the importance of preventing and addressing factors contributing to these changes to prevent possible malignant transformation of the epithelium.