Stage IV includes: IVA: (T4, N0, M0); (T4, N1, M0); (T4, N2, M0); IVB (Any T, N3, M0); IVC (Any T, Any N, M1). T4: Tumor with intracranial extension and/or involvement of cranial nerves, infratemporal fossa, hypopharynx, orbit, or masticator space. N3: Metastasis in a lymph node(s). N3a: greater than 6 cm in dimension. N3b: extension to the supraclavicular fossa. M1: Distant metastasis. (AJCC 6th ed.) [from NCI]