A4.

TNM staging of head and neck mucosal melanoma (AJCC 8th edition)

Stage	Criteria
AJCC, American Joint Committee on Cancer.
T stage
T3	Tumor is restricted to mucosa and its proximate soft tissues, irrespective of tumor thickness and the maximum diameter, e.g. nasal polypoid melanoma and melanotic or amelanotic melanoma of oral cavity, pharynx and larynx
T4	Moderately aggressive or highly aggressive
T4a	Moderately aggressive: tumor invades deep soft tissues, cartilage, bone or surface skin, low cranial nerve (IX, X, XI, XII), masticator space, carotid artery, gap before the spine or mediastinal structure
T4b	highly aggressive: tumor invades brain, cranial dura, skull base
N stage
NX	Regional lymph node not evaluated
N0	Without regional lymph node
N1	With regional lymph node
M stage
M0	Without distant metastasis
M1	With distant metastasis