Book excerpt: This book includes more clinical aspects and concentrates on cancer and precancer of the oral mucosa rather than attempting to cover all benign and malignant tumours of the oral and oropharyngeal tissue. One main emphasis is the significance of the clinical features of the various lesions discussed. Attention is also drawn to those conditions particular to the oral mucosa that may give rise to appearances which are important in differential diagnoses but can be misleading to those who do not have detailed knowledge of the tissue involved. The TNM-classification for malignant tumours of the lip and oral cavity is also included.