Recurrent choroidal melanoma after transscleral local resection with diffuse vitreous seeding

Abstract

Background: Choroidal melanoma usually spreads systemically via the vascular system or extraocularly through channels in the sclera. Intraocular spread through vitreous seeding is uncommon.

Methods: We present two patients in whom melanoma recurred following transscleral local resection and widespread fine patchy pigmentation of the retina was identified grossly. The eyes were submitted for histological examination.

Results: In one case there was recurrent melanoma in the surgical coloboma with diffuse vitreous seeding and a pre-retinal membrane composed of tumour cells. Tumour cells were also identified in the anterior chamber. In the second case there was no tumour in the coloboma although two small satellite choroidal nodules were identified. Tumour cells were also present in the vitreous and covering the surface of the retina.

Conclusions: We described two cases of recurrent choroidal melanoma following transscleral local resection with vitreous seeding. Intraocular seeding following local resection is uncommon. There are several potential mechanisms for this although it seems likely that in these cases loss of the retinal barrier assisted in the intraocular spread of these tumours.