Source:http://linkedlifedata.com/resource/umls/id/C1377919
NCI: Stage IV nasopharyngeal cancer is divided into stages IVA, IVB, and IVC. In stage IVA, cancer has spread beyond the nasopharynx and may have spread to the cranial nerves, the hypopharynx (bottom part of the throat), areas in and around the side of the skull or jawbone, and/or the bone around the eye. Cancer may have spread to one or more lymph nodes on one or both sides of the neck and/or to lymph nodes behind the pharynx, and the affected lymph nodes are 6 centimeters or smaller. In stage IVB, cancer has spread to lymph nodes between the collarbone and the top of the shoulder and/or the affected lymph nodes are larger than 6 centimeters. In stage IVC, cancer has spread beyond nearby lymph nodes to other parts of the body.,NCI: 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