Cancer of unknown primary of the head and neck TNM

Scottish Cancer Network: Clinical Management Pathways
NHS National Services Scotland
Scottish Cancer Network logo

TNM Classification of Malignant Tumours (8th Edition, UICC, 2017)

 

EBV or HPV/p16 negative or unknown

Primary Tumour (T)

T0       No evidence of primary tumour

 

Regional Lymph Nodes (N)

N1       Metastasis in a single lymph node, 3 cm or less in greatest dimension without extranodal
extension

N2       Metastasis described as:

N2a     Metastasis in a single lymph node, more than 3 cm but not more than 6 cm in greatest
dimension without extranodal extension

N2b     Metastasis in multiple ipsilateral lymph nodes, none more than 6 cm in greatest
dimension, without extranodal extension

N2c     Metastasis in bilateral lymph nodes, none more than 6 cm in greatest dimension,
without extranodal extension

N3a     Metastasis in a lymph node more than 6 cm in greatest dimension without extranodal
extension

N3b     Metastasis in a single or multiple lymph nodes with clinical extranodal extension*

Notes: * The presence of skin involvement or soft tissue invasion with deep fixation/tethering to
underlying muscle or adjacent structures or clinical signs of nerve involvement is classified as
clinical extra nodal extension.

Midline nodes are considered ipsilateral nodes.

 

Distant Metastasis (M)


M0 No distant metastasis

M1 Distant metastasis

Pathological classification of Regional Lymph Nodes (pN)


Histological examination of a selective neck dissection specimen will ordinarily include 10 or
more lymph nodes. Histological examination of a radical or modified radical neck dissection
specimen will ordinarily include 15 or more lymph nodes.

pN1      Metastasis in a single lymph node, 3 cm or less in greatest dimension without extranodal
extension

pN2      Metastasis described as:

pN2a    Metastasis in a single lymph node, 3 cm or less in greatest dimension with
extranodal extension or more than 3 cm but not more than 6 cm in greatest
dimension without extranodal extension

pN2b    Metastasis in multiple ipsilateral lymph nodes, none more than 6 cm in greatest
dimension, without extranodal extension

pN2c    Metastasis in bilateral lymph nodes, none more than 6 cm in greatest dimension,
without extranodal extension

pN3a    Metastasis in a lymph node more than 6 cm in greatest dimension without extranodal
extension

pN3b    Metastasis in a lymph node more than 3 cm in greatest dimension with extranodal
extension or multiple ipsilateral, or any contralateral, or bilateral node(s) with extranodal
extension