Stage I Nasopharyngeal Carcinoma AJCC v9

**Semantic type:** Neoplastic Process

**Definition:** Stage I includes: IA: (T1-T2, N0, M0); IB: (T0-T2, N1, M0). T0: No evidence of primary tumor identified, but EBV-positive cervical node(s) involvement is present. T1: Tumor confined to nasopharynx or tumor extension to any of the following without parapharyngeal involvement: oropharynx, nasal cavity. T2: Tumor extension to any of the following: parapharyngeal space, adjacent soft tissue involvement of medial pterygoid, lateral pterygoid, prevertebral muscles. N0: No tumor involvement of regional lymph node(s). N1: Tumor involvement of any of the following: unilateral cervical lymph node(s), unilateral or bilateral metastasis in retropharyngeal lymph node(s), and all of the following: 6 cm or less in greatest dimension, above the caudal border of cricoid cartilage, without advanced extranodal extension. M0: No distant metastasis. (AJCC 9th ed.)