Choroidal nevus can cause overlying chronic retinal pigment epithelium (RPE) degenerative features, but frank retinal invasion is exquisitely rare.
This is a retrospective review of 8 cases of choroidal nevus with retinal invasion with evaluation of clinical and imaging features.
At the time of diagnosis of choroidal nevus with retinal invasion, mean patient age was 65 years. Mean tumor basal diameter was 7 mm, and mean thickness was 2.3 mm. Retinal invasion was ophthalmoscopically visible in all eyes. Related features included drusen (n = 4/8) and RPE fibrous metaplasia (n = 2/8). Overlying lipofuscin, subretinal fluid, RPE detachment, and retinal edema were absent. On B-scan ultrasonography, the lesion was dome-shaped (n = 7/7) and echo-dense (n = 6/7). Optical coherence tomography demonstrated outer retinal invasion (n = 8/8) with additional inner retinal invasion (n = 3/8). The tissue was hypoautofluorescent at the site of invasion (n = 6/7). Over a mean follow-up of 40 months, tumor enlargement was detected in 2 eyes and managed with observation (< 1 mm enlargement) or plaque radiotherapy (5 mm enlargement). Nevus hypoautofluorescence was correlated with nevus stability (p = 0.035).
Retinal invasion of the choroidal nevus is rare. In this series of 8 cases, only 1 demonstrated transformation to melanoma over a mean interval of 40 months. Long-term monitoring of such lesions is warranted.