Epithelial Dysplasia: Carcinoma• Epithelial Dysplasia (上皮細胞發育異常)• Abnormal development of tissues in the vocal fold mucosa, or other sites of the larynx• Are the squamous cell type & originate from the epithelium, which will invade the deeper layers & vocalis muscle• Caused by chronic irritation of the laryngeal epithelium & mucosa by tobacco smoke & alcohol