Choroidal melanoma arising from optic disc melanocytoma with associated pathology and genetic findings case report.

Purpose: Choroidal melanoma arising from an optic disc melanocytoma is rare but has been previously described at an incidence of 1-2%. Evaluating these cases for pathology and genetics is relevant for determining metastatic risk.

Methods: Case report.

Results: A 73 year-old male with a history of optic disc melanocytoma of the left eye presented with blurred vision after being lost to follow up at an outside clinic for five years. The melanocytoma was found to have undergone transformation to a choroidal melanoma suggested by fundus examination, optical coherence tomography (OCT), and B scan ultrasonography. The patient underwent enucleation as the tumor was circumpapillary and technically unable to undergo plaque brachytherapy. Pathologic evaluation after enucleation demonstrated peripapillary choroidal melanoma of mixed cellularity with areas of intrascleral extension. Genetic analysis revealed mutations in guanine nucleotide-binding protein G(q) subunit alpha (GNAQ) and exon 1 of eukaryotic translation initiation factor 1A, X-linked (EIF1AX) and a Class 1A molecular signature.

Conclusion: Our case of a choroidal melanoma of low metastatic risk arising from an optic disc melanocytoma may suggest that these cases have a lower metastatic risk than melanomas not derived from melanocytomas though further studies including cases with genetic profiling and long-term systemic follow up to detect metastatic disease rates are necessary to establish such a pattern.