Cervical lymph node (staging)
Cervical lymph node staging refers to evaluating regional nodal metastasis from primary cancer of the head and neck. The following article reflects the 8th edition of the TNM staging system published by the American Joint Committee on Cancer, which is used for staging starting January 1, 2018 . This system applies for epithelial cancers (most commonly squamous cell carcinoma) of most regions of the head and neck, including those of the skin, maxillary sinus, nasal cavity and ethmoid sinus, oral cavity, oropharynx, major salivary glands, hypopharynx, larynx, and unknown primary. Notable exclusions of head and neck cancers are HPV-related oropharynx cancer, nasopharynx cancer, mucosal melanoma, and thyroid cancers (differentiated, medullary, or anaplastic).
Cervical nodal staging categorizes metastatic lymph nodes according to location, multiplicity, size measured in greatest dimension, and presence of extranodal extension (ENE). The emphasis on ENE is new since prior editions. Nodal involvement can be evaluated clinically (cN) or pathologically (pN). The major difference between the two surrounds categorization of a node measuring 3 cm or less with extranodal extension. Clinically overt ENE in a node measuring 3 cm or smaller is cN3b but pathologic ENE in a similarly sized node would be pN2a, reflecting the higher bar to demonstrate clinically overt ENE.
Clinical determination of ENE requires unambiguous findings on physical examination and supporting radiological evidence; radiologic evidence is insufficient . These findings are skin invasion, muscular infiltration, dense tethering/fixation to adjacent structures, or neural invasion with dysfunction involving a cranial nerve, the brachial plexus, the sympathetic trunk, or the phrenic nerve.
Clinical nodal status (cN)
Clinical criteria apply for patients treated nonsurgically, without cervical lymph node dissection. Clinical evaluation synthesizes information from such sources as physical examination, imaging, and fine-needle aspiration.
- NX: nodes cannot be assessed
- N0: no regional node metastases
- N1: metastasis in single ipsilateral node, ≤3 cm, and no extranodal extension (ENE(−))
- N2
- N2a: metastasis in single ipsilateral node, >3 cm and ≤6 cm, and ENE(−)
- N2b: metastasis in multiple ipsilateral nodes, all ≤6 cm, and ENE(−)
- N2c: metastasis in bilateral or contralateral nodes, all ≤6 cm, and ENE(−)
- N3
- N3a: metastasis in a node, >6 cm, and ENE(−)
- N3b: metastasis in a node with clinically overt ENE(+) (ENEc)
Pathologic nodal status (pN)
Pathologic criteria apply for patients treated surgically, with cervical lymph node dissection, for whom multiple whole lymph nodes are available for microscopic evaluation.
- NX: nodes cannot be assessed
- N0: no regional node metastases
- N1: metastasis in single ipsilateral node, ≤3 cm, and no extranodal extension (ENE(−))
- N2
- N2a: metastasis in single ipsilateral node, >3 cm and ≤6 cm, and ENE(−); or metastasis in single ipsilateral node, ≤3 cm, and ENE(+)
- N2b: metastasis in multiple ipsilateral nodes, all ≤6 cm, and ENE(−)
- N2c: metastasis in bilateral or contralateral nodes, all ≤6 cm, and ENE(−)
- N3
- N3a: metastasis in a node, >6 cm, and ENE(−)
- N3b: metastasis in single ipsilateral node, >3 cm, and ENE(+); or multiple ipsilateral, contralateral, or bilateral nodes any with ENE(+); or single contralateral node of any size and ENE(+)
See also
