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What is N-3 TNM staging of head and neck tumors shows: and explain in detail?
8th AJCC (2017) TNM Classification of Carcinoma Lip & Oral Cavity Primary Tumor (T) Regional Lymph Nodes (N) Tis Carcinoma in situ. N1 Metastasis in a single ipsilateral LN, <3 cm in greatest dimension without extranodal extension T1 Tumor <2cm in greatest dimension & <5cm depth of invasion N2a Metastasis in a single ipsilateral LN, >3 cm but <6 cm in greatest dimension without extranodal extension T2 Tumor <2cm in greatest dimension & >5 mm but <10 mm depth of invasion or tumor >2 cm but <4 cm in greatest dimension & depth of invation < 10 mm N2b Metastaes in a multiple ipsilateral LN, none >6 cm in greatest dimension without extranodal extension T3 Tumor >4 cm in greastest dimension and >10 mm depth of invasion N2c Metastases in bilateral or contralateral LN, none >6cm in greatest dimension without extranodal extension T4a Lip: Tumor invades through coical bone, inferior alveolar nerve, floor of mouth, or skin (of chin or nose) N3a Metastasis in a LN >6cm in greatest dimension without extranodal extension N3b Metastasis in a single or multiple LNs with clinical extranodal extension Oral cavity: Tumor invades through coical bone mandible or maxillary sinus or invades the skin of face Distant Metastasis T4b Tumor invades masticator space, pterygoid plates, or skull base and/or encases internal carotid aery M0 No distant metastasis. M1 Distant metastasis.