Primary tumor (T)
- TX: lymphoma extent not specified
- T0: no evidence of lymphoma
- T1: lymphoma involving the conjunctiva alone without orbital involvement
- T1a: bulbar conjunctiva alone
- T1b: palpebral conjunctiva, +/- fornix, +/- caruncle
- T1c: extensive conjunctival involvement
- T2: lymphoma with orbital involvement +/- any conjunctival involvement
- T2a: anterior orbital involvement (+/- any conjunctival involvement)
- T2b: anterior orbital involvement (+/- any conjunctival involvement but with lacrimal involvement)
- T2c: posterior orbital involvement (+/- any conjunctival involvement, +/- anterior involvement, +/- any extraocular muscle involvement)
- T2d: nasolacrimal drainage system involvement (+/- conjunctival involvement but not including nasopharynx)
- T3: lymphoma with preseptal eyelid involvement (infiltrates preseptal tissues such as dermis or orbicularis muscle of anterior eyelid skin) +/- orbital involvement, +/- any conjunctival involvement
- T4: orbital adnexal lymphoma extending beyond orbit to adjacent structures such as bone and brain
- T4a: involvement of nasopharynx
- T4b: osseous involvement (including periosteum)
- T4c: involvement of maxillofacial, ethmoidal or frontal sinuses
- T4d: intracranial spread