Stage IVB includes: (T4b, Any N, M0); (Any T, N3, M0). T4b: Very advanced local disease. Tumor invades any of the following: orbital apex, dura, brain, middle cranial fossa, cranial nerves other than maxillary division of trigeminal nerve (V2), nasopharynx, or clivus. N3: Metastasis in a lymph node larger than 6 cm in greatest dimension and ENE(-); or metastasis in a single ipsilateral node larger than 3 cm in greatest dimension and ENE(+); or metastases in multiple ipsilateral, contralateral or bilateral nodes, any with ENE(+). M0: No distant metastasis. (AJCC 8th ed.) [from NCI]