A patient has carcinoma of the right tongue on its lateral border of anterior 2/3rd, with lymph node of size 4 cm in level 3 on the left side of the neck, stage of the disease is -

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.