I wrote the first edition of this work in 1987 with the object of providing a review of the aetiology, pathogenesis and morphological basis of diseases of the ear, nose and throat. Since that time important changes have taken place in the disciplines of both histopathology and otorhinolaryngology. Pathology has shifted its research orientation towards a molecular one; notable successes with new medical and surgical treatments in ENT have resulted in a striking expansion of that field. To provide a precis of the scientific principles of a subject lying between two such mobile territories was a daunt­ ing prospect. Help was indeed necessary and I welcome Henrik Hellquist as the co­ author of this second edition. He has had a longstanding interest in both head and neck and molecular pathology and has not only produced scholarly publications, but has also played an important role in enhancing international cooperation in this combined field.