<prompt> A patient has carcinoma of the right tongue on its lateral border of anterior 23rd, with lymph node of size 4 cm in level 3 on the left side of the neck, stage of the disease is -N0N1N2N3  <response>: According to the American Joint Committee on Cancer AJCC, 2002, the regional lymph node staging N is common to all head and neck sites, except the nasopharynx.So, T classification is specific to different sites of origin while regional lymph node N staging is common to all head neck sites, except the nasopharynx. 