Suspected vitreous seeding of uveal melanoma
Reviewed by Jonathan Chan

This is a retrospective non-randomised study of 23 patients with consecutive uveal melanoma who underwent diagnostic vitrectomy between the period of January 2000 and November 2013. The reason for vitrectomy was suspected dissemination of tumour cells inside the eye. The aim of the study was to review all cases of suspected vitreous seeding of treated or untreated uveal melanoma in the clinic and to compare clinical, psychological and histological findings with patients’ survival. This study included 23 patients with a mean age of 66 years. Four patients presented pigmented vitreous debris at initial presentation prior to the treatment of the uveal melanoma. All but one of these four patients had been enucleated as a consequence of cytology-proven vitreous spreading of vital melanoma cells. The remaining 19 patients presented pigmented vitreous debris at a mean of 60 months following local tumour treatment. Thirteen of these patients had been treated with a ruthenium plaque (mean scleral dose of 1295 Gy, mean apex dose 152 Gy), three with binuclid plaque (mean scleral dose 1005 Gy, mean apex dose 70 Gy) and three proton beam radiation. Of the 19 patients, 10 showed only melanophages in the vitreous specimen, while the remaining nine patients had vital tumour cells in vitreous cytology. Four out of these nine patients had been enucleated in the course of follow-up. During the follow-up of the cohort of 23 patients, four patients died, but only one of them due to metastatic disease. The authors concluded from this small cohort study that obtaining a vitreous specimen helps to distinguish melanophages from vital tumour cells. They could not observe an increased risk of metastasis in patients who showed melanoma cell dissemination inside the eye, compared with those patients only showing melanophages. Therefore, the authors suggested re-evaluating the necessity of enucleation in each patient. In addition, the authors also suggested that the biology of the uveal melanoma determines the patients’ tumour-related survival much more than possible vitreous spreading of the tumour inside the eye.

Suspected vitreous seeding of uveal melanoma: relevance of diagnostic vitrectomy.
Metz CH, Bornfeld N, Metz KA, Gök M.
BRITISH JOURNAL OF OPHTHALMOLOGY
2016;100:660-4.