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

N1 Metastasis in a single epsilateral lymphnode 3cm or less in greatest dimension

N2 Metastasis in single or multiple ipsilateral or bilateral lymphnodes

N2a • Metastasis in single ipsilateral lymphnode >3cm but <6cm

• Multiple ipsilateral lymphnodes <6cm• Bilateral lymphnodes <6cm

N2b Metastasis in multiple ipsilateral lymphnodes <6cm

N2c Metastasis in bilateral lymphnodes <6cm

N3 Metastasis in lymphnodes >6cm

M Distant metastasis

MX Presence of distant metastasis cannot be assessed

MO No distant metastasis

M1 Distant metastasis