Non-contiguous recurrence or secondary choroidal melanoma following plaque radiotherapy

Non-contiguous local recurrence of posterior uveal melanoma occurs rarely after plaque therapy. A 50-year-old white first presented with choroidal melanoma. He underwent therapy with episcleral iodine-125 radioactive plaque therapy. Nine years later fundus evaluation revealed a new pigmented lesion in the inferotemporal equatorial area. Patient was considered to have a non-contiguous recurrent melanoma and the eye was enucleated. Histologic microscopic examination disclosed a 3 x 1.8 mm densely pigmented tumour internal to the choroid at the equator. The tumour was composed of large round cells with round nuclei, prominent nucleoli, abundant cytoplasm and spindle-shaped cells with spindle-shaped nuclei and prominent nucleoli. The tumour extended through the retina. The superior nasal area of plaque therapy had extensive chorioretinal atrophy with loss of retinal pigment epithelium, thinning of the retina and thinning and depigmentation of the choroids. Within this area of atrophy, there was a pigmented lesion composed by densely packed, spindle-shaped cells with spindle-shaped nuclei. Our patient illustrated non-contiguous recurrence of choroidal melanoma, such finding raises concerns about physiopathology and treatment of choroidal melanoma.