This reference uses AJCC 8, confirmed current for this site on 4 November 2026. UICC TNM 9th edition, effective in 2026, is a separate system. Record organisation, edition, anatomical location and the c/p/yc/yp prefix. AJCC · UICC.
For choroid/ciliary body AJCC 8 combines tumour size category, ciliary-body involvement, extraocular extension, N and M. Iris melanoma has separate T definitions and does not use the conventional prognostic stage-group scheme.
Tumour-size categories and T
Choroidal/ciliary-body tumours are assigned size category 1-4 using both largest basal diameter and thickness. A single diameter is insufficient to infer the AJCC category.
| T subcategory | Concept | Note |
|---|---|---|
| T1-T4 | Size category 1-4 | Based on size matrix of diameter and thickness. |
| a | Neither ciliary-body involvement nor extraocular extension | Specific to the size category. |
| b | Ciliary-body involvement without extraocular extension | Can alter prognostic group. |
| c/d | Extraocular extension ≤5 mm and ciliary-body status | Check the full site-specific AJCC matrix. |
| T4e | Extraocular extension >5 mm | Special T4e rule regardless of size category. |
Choroid and ciliary-body prognostic groups
| Stage | Typical AJCC 8 T (N0 M0) | Interpretation |
|---|---|---|
| I | T1a | Size category 1, no ciliary or extraocular spread. |
| IIA | T1b-d, T2a | Smaller lesions with additional features or size category 2. |
| IIB | T2b, T3a | Intermediate local group. |
| IIIA | T2c-d, T3b-c, T4a | Larger or more extensive local disease. |
| IIIB | T3d, T4b-c | More advanced local disease. |
| IIIC | T4d-e | Most advanced local disease. |
| IV | Any T with N1 or M1 | Regional or distant metastatic disease. |
Iris melanoma - separate T classification
Iris T1 describes iris-confined disease by clock hours and glaucoma; T2 includes ciliary-body/choroidal extension; T3 scleral extension; T4 extraocular spread. AJCC 8 does not define prognostic stage groups for iris melanoma, even though its TNM is documented.
Stage is not molecular risk
Risk biomarkers such as monosomy 3, BAP1 status and GEP class 1/2 may refine prognosis but do not replace AJCC TNM. Metastatic classification also documents distant lesion dimensions when defining M substages.
Extensive local disease without distant spread is not automatically stage IV. Metastatic uveal melanoma is stage IV regardless of primary tumour size.
Clinical references
NCI Uveal Melanoma PDQ; AJCC current editions. Use the official diameter/thickness matrix to assign exact T.
Other staging systems
Educational reference, not a substitute for specialist MDT review or official AJCC protocols. Record the edition used and do not infer a stage group from a single image.