Spontaneous Necrosis of a Large Choroidal Melanoma: Unusual Presentation in a 49-Year-Old Male.

PURPOSE: To demonstrate a case of massive vitreous haemorrhage obscuring the underlying diagnosis of a large mixed-cell choroidal melanoma which had undergone spontaneous necrosis. CASE REPORT: A 49-year-old man in good general health suddenly lost vision in his right eye due to an extensive vitreous haemorrhage 1 day after a workout at the gym. He reported good vision prior to that without any symptoms of flashes, floaters, or shadows. He was referred to the vitreoretinal department of a tertiary eye hospital, where he presented with a drop in vision to light perception only in the right phakic eye. Pars plana vitrectomy was performed in the right eye, which revealed intraoperatively massive retinal ischemia and choroidal haemorrhage, but no obvious tumour mass that could have been biopsied. The vitrectomy cassette specimen was sent for histopathology, where "ghost-like" melanoma cells were identified. The eye was subsequently enucleated, revealing an extensively necrotic and haemorrhagic choroidal melanoma of mixed cell type with only small viable tumour foci at the base and almost complete lysis of the detached retina.
CONCLUSION: Some uveal melanomas (UMs) undergo spontaneous necrosis due to rapid growth, with the centre of the tumour outstripping its established blood supply in the "watershed area" of the eye, and becoming hypoxic with associated necrosis of intraocular structures. Such UMs are often associated with haemorrhage and/or inflammation and usually cause significant destruction of ocular tissues, resulting in enucleation as the only treatment option.