Choroidal nevus with retinal invasion, clinical and imaging features

Purpose

To report a clinically challenging case of a choroidal nevus with retinal invasion with accompanying ancillary testing.

Observations

A 60-year-old Caucasian female was referred for a suspicious melanocytic choroidal lesion in her left eye. Ophthalmoscopic examination revealed a melanocytic choroidal lesion, measuring 10 mm × 10 mm in basal diameter. The lesion had a clinically evident area of retinal invasion seen as a protruding choroidal mass at its center, darker in appearance compared to the rest of the lesion, obscuring retinal vessels. The choroidal nevus had associated chronic retinal changes and the absence of overlying orange pigment or subretinal fluid. On fundus autofluorescence, there was a hypoautofluorescent area showing the site of retinal invasion. Fluorescein angiography at the lesion site exhibited central blocked perfusion corresponding to the area of retinal invasion. Ultrasonography showed a dome-shaped choroidal lesion that was optically dense with a medium-high internal reflectivity measuring 3.3mm in thickness. The optical coherence tomography showed a choroidal mass extruding through a break in Bruch's membrane with inner retinal invasion. A watchful waiting strategy was adopted, and at 28 months follow-up, the choroidal lesion did not show growth or presence of new suspicious features of malignant transformation.

Conclusion and importance

This case highlights the importance of recognizing the key features of choroidal nevi with retinal invasion, which can prevent the treatment of a benign condition and assist in the arrival of a correct diagnosis. These lesions should be monitored for long-term.

Choroidal Nevus with Retinal Invasion in 8 Cases

Purpose

Choroidal nevus can cause overlying chronic retinal pigment epithelium (RPE) degenerative features, but frank retinal invasion is exquisitely rare.

Procedures

This is a retrospective review of 8 cases of choroidal nevus with retinal invasion with evaluation of clinical and imaging features.

Results

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).

Conclusion

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.

Mechanisms of Optic Nerve Invasion in Primary Choroidal Melanoma

Aim

The aim of this study was to assess morphological risk factors associated with optic nerve invasion of choroidal melanoma and to identify possible mechanisms of optic nerve invasion.

Methods

Medical charts and histology slides of patients with primary choroidal melanoma who were treated by enucleation/exenteration and whose pathology showed optic nerve invasion were reviewed.

Results

Twenty-one patients (mean age: 65.67 ± 14.72 years) with primary uveal melanoma arising from the choroid were included in this analysis. A peripapillary location was present in 86% of the cases. Four types of optic nerve invasion were identified: transvitreal invasion (10%); retinal invasion (23%); direct peripapillary invasion (57%); and a combined mechanism (10%). Optic nerve invasion was prelaminar in 67%, laminar in 10%, and retrolaminar in 23% of the cases. Significantly higher largest basal diameter (p = 0.021) and tumor thickness values (p = 0.017) and higher rates of vortex vein (p = 0.022) and retinal invasion (p = 0.007) were observed in the transvitreal/retinal invasion groups when compared to the direct peripapillary invasion group.

Conclusions

A peripapillary tumor location was the most common mechanism of optic nerve invasion of choroidal melanoma. In 43% of the cases, other mechanisms including transvitreal and retinal invasion resulted in optic nerve invasion.