THE SMALL FATAL CHOROIDAL MELANOMA STUDY A Survey by the European Ophthalmic Oncology Group

ABSTRACT Purpose To determine the size at which choroidal melanomas can metastasize and to report the characteristics of small fatal choroidal melanomas (SFCM). Design Retrospective case series. Methods Ten ocular oncology services submitted 45 patients with a choroidal melanoma 3 mm or less in thickness and 9 mm or less in largest basal diameter (LBD), when treated, who developed metastases. Results Median tumor thickness was 2.4 mm (range, 1.0-3.0) and LBD 7.3 mm (range, 3.0-9.0). Of 14 (31%) tumors that were first observed, 12 grew a median of 0.5 mm (range, 0.1-1.2) in thickness and 1.0 mm (range, 0-3.0) in LBD within a median of 7 months; 3 were initially smaller than 3 mm in LBD. Number of risk factors for growth and metastasis was 0 for 4% of the tumors; 60% were over 2 mm in thickness, 63% had subretinal fluid, 84% caused symptoms, 57% had orange pigment, and 92% were within 3 mm of the disk. Local recurrence occurred in 8 (26%) of 31 eyes treated conservatively. Median metastasis-free survival was 4.5 years (range, 0.8–15.7). Kaplan-Meier estimate of metastasis developing was 15% (95% CI, 7-26), 51% (95% CI, 36-64) and 85% (95% CI, 71-92) by 2, 5 and 10 years, respectively. By the time of analysis, 37 patients had died of metastasis after a median of 7 months. Conclusions Choroidal melanomas less than 3.0 mm in LBD are highly unlikely to metastasize. Risk factors of a SFCM are similar to those for all choroidal melanomas of similar size.