RETINOINVASIVE MALIGNANT-MELANOMA OF THE UVEA

Aims-To define a retinoinvasive phenotype of uveal melanoma based on a n informative case and survey of literature. Methods-A 65-year-old wom an developed a circumscribed mixed cell type melanoma of the ciliary b ody that was locally excised. After 6 years, secondary glaucoma evolve d. Three years later a ring melanoma was diagnosed and the eye was enu cleated. The histopathological material was analysed by immunohistoche mistry.Results-A spindle cell type ring melanoma infiltrated the iris and ciliary body diffusely, and extended through the aqueous outflow c hannels and iridocyclectomy flap extrasclerally. The choroid was uninv olved. Instead, tumour cells spread to the citreous and along the cili ary epithelium, adhered to the hyaloid face and retinal surface, and e xtensively invaded the neuroretina, the retrobulbar optic nerve, and p erineural space. They were labelled for S-100 protein, vimentin, and i n the neuroretina for cytokeratins 8 and 18. No evidence of systemic d isease is evident 5 years after enucleation. Three identical tumours o f the iris and ciliary body that extensively infiltrated the neuroreti na and retrobulbar optic nerve were identified fi om previous literatu re. Conclusion-Retinoinvasive melanoma is a rare but distinct phenotyp e of uveal melanoma, different hom circumscribed and most diffuse mela nomas that may erode the overlying retina and infiltrate the optic ner ve but that do not invade non-adjacent retina. Retinoinvasive tumours tend to evolve from a ring melanoma and they grow slowly, which may fa vour emergence of tumour clones able to migrate, adhere to, and invade into the neuroretina, analogous to the metastatic cascade. Frequent s econdary angle closure glaucoma may promote invasion into the optic ne rve.