The TNM-classification of the UICC is used for staging malignant tumours worldwide. From 2003 the new revised sixth edition must be used. In comparison with the fifth edition there are some general and some head and neck carcinoma specific alterations. Some designations are introduced if sentinel lymph node procedure or immunohistochemistry or molecular methods have been used. In the revised version some definitions for advanced tumour stages at several head and neck sites are changed. In the new classification of the primary tumour the terms erosion and invasion of cartilage or bone are used. At most head and neck sites T4 is divided in T4a and T4b
