Choroidal naevus

This is a very common, benign choroidal tumour composed of melanocytes. Choroidal naevi are typically incidentally discovered, asymptomatic, pigmented lesions. Up to 15 per cent appear non-pigmented or amelanotic. They are usually composed of spindle-shaped cells with small nuclei, inconspicuous nucleoli and without mitotic figures.

While the principal challenge for the clinician is to differentiate a choroidal naevus from a malignant melanoma, non-malignant complications are also possible.

When sub-retinal fluid accumulates at the macula in the vicinity of a naevus, serous macular detachment can affect vision. Choroidal neovascularisation and vitreous haemorrhage are other, rare, complications.

SYMPTOMS

Asymptomatic in the vast majority of cases. Serous macular detachment may present with monocular blurred vision. Photopsias (flashing lights) in the presence of a pigmented choroidal tumour increase the likelihood of malignancy.