1. T Primary tumour
TX Primary tumour cannot be assessed
TO No evidence of primary tumour
Tis Carcinoma in situ
T1 Tumour 2cm or less in greatest dimension
T2 Tumour >2cm but <4cm
T3 Tumour >4cm in greatest dimension
T4 Tumour invades adjacent structures
N Regional lymphnodes
NX Regional lymphnodes cannot be assessed
NO No regional lymphnode metastasis M Distant metastasis
MX Presence of distant
N1 Metastasis in a single epsilateral lymphnode 3cm metastasis cannot be
or less in greatest dimension assessed
N2 Metastasis in single or multiple ipsilateral or
bilateral lymphnodes MO No distant metastasis
N2a • Metastasis in single ipsilateral
M1 Distant metastasis
lymphnode >3cm but <6cm
• Multiple ipsilateral lymphnodes <6cm
• Bilateral lymphnodes <6cm
N2b Metastasis in multiple ipsilateral lymphnodes
<6cm