Primary tumor (T) |
T category | T criteria |
TX | Primary tumor cannot be assessed |
T0 | No evidence of primary tumor |
Tis | Carcinoma in situ |
T1 | Tumor ≤10 mm in greatest dimension |
T1a | Tumor does not invade the tarsal plate or eyelid margin |
T1b | Tumor invades the tarsal plate or eyelid margin |
T1c | Tumor involves full thickness of the eyelid |
T2 | Tumor >10 mm but ≤20 mm in greatest dimension |
T2a | Tumor does not invade the tarsal plate or eyelid margin |
T2b | Tumor invades the tarsal plate or eyelid margin |
T2c | Tumor involves full thickness of the eyelid |
T3 | Tumor >20 mm but ≤30 mm in greatest dimension |
T3a | Tumor does not invade the tarsal plate or eyelid margin |
T3b | Tumor invades the tarsal plate or eyelid margin |
T3c | Tumor involves full thickness of the eyelid |
T4 | Any eyelid tumor that invades adjacent ocular, orbital, or facial structures |
T4a | Tumor invades ocular or intraorbital structures |
T4b | Tumor invades (or erodes through) the bony walls of the orbit or extends to the paranasal sinuses or invades the lacrimal sac/nasolacrimal duct or brain |
Regional lymph nodes (N) |
N category | N criteria |
NX | Regional lymph nodes cannot be assessed |
N0 | No evidence of lymph node involvement |
N1 | Metastasis in a single ipsilateral regional lymph node, ≤3 cm in greatest dimension |
N1a | Metastasis in a single ipsilateral lymph node based on clinical evaluation or imaging findings |
N1b | Metastasis in a single ipsilateral lymph node based on lymph node biopsy |
N2 | Metastasis in a single ipsilateral lymph node, >3 cm in greatest dimension, or in bilateral or contralateral lymph nodes |
N2a | Metastasis documented based on clinical evaluation or imaging findings |
N2b | Metastasis documented based on microscopic findings on lymph node biopsy |
Distant metastasis (M) |
M category | M criteria |
M0 | No distant metastasis |
M1 | Distant metastasis |
Prognostic stage groups |
When T is... | And N is... | And M is... | Then the stage group is... |
Tis | N0 | M0 | 0 |
T1 | N0 | M0 | IA |
T2a | N0 | M0 | IB |
T2b-c, T3 | N0 | M0 | IIA |
T4 | N0 | M0 | IIB |
Any T | N1 | M0 | IIIA |
Any T | N2 | M0 | IIIB |
Any T | Any N | M1 | IV |