Table 1: Pathologic TNM (pTNM) version 8 of the American Joint Committee on Cancer staging [8].

pTpNpM

pTX: Pprimary tumour cannot be assessedpNX: Rregional lymph nodes cannot be assessedpM1: Distant metastasis with histopathological confirmation
pTO: Nno evidence of primary tumourpNO: Nno regional lymph node involvementpM1a: histopathological confirmation of tumour at any distant site (bone marrow, liver, or others)
pT1: iintraocular tumour(s) without any local invasion, focal choroidal invasion, or pre- or intra-laminar invasion of the optic nerve headpN1: regional lymph node involvementpM1b: histopathological confirmation of tumour in the CSF fluid or CNS parenchyma
pT2: intraocular tumour(s) with minimum local invasion
pT2a: intraocular tumour(s) with local invasion-focal choroidal invasion, pre- or intra-laminar invasion of the optic nerve head
pT2b: intraocular tumour(s) with invasion of stroma iris and/or trabecular meshwork and/or Schlemm’s canal
pT3: intraocular tumour(s) with significant local invasion
pT3a: iintraocular tumour(s) with massive choroidal invasion in largest diameter, or multiple foci of focal choroidal invasion totaling >3 mm, or any full thickness choroidal invasion
pT3b: intraocular tumour(s) with post-laminar invasion of the optic nerve but not up to the end of its surgical margin
pT3c: intraocular tumour(s) with any partial thickness involvement of sclera within the inner two-thirds
pT3d: intraocular tumour(s) with full -thickness into the outer -third of the sclera and/or invasion into or around emissary channels
pT4: evidence of extraocular tumour: positive surgical margin of the optic nerve, full -thickness of the sclera, extra-ocular muscle, orbital bone, conjunctive, or eyelids