Is optical coherence tomography angiography helpful in the differential diagnosis of choroidal nevus versus melanoma?

Purpose: To describe the imaging features of choroidal nevus and melanoma using optical coherence tomography angiography, and evaluate the ability of this technique to establish the differential diagnosis based on the display of the tumor’s intrinsic vasculature. Methods: Comparative analysis of optical coherence tomography angiography findings in consecutive patients diagnosed with choroidal nevus or choroidal melanoma following a complete ophthalmic evaluation, including best-corrected visual acuity and several imaging studies: color fundus photography, B-scan ultrasound, spectral-domain optical coherence tomography, and optical coherence tomography angiography. Optical coherence tomography angiography was used to investigate qualitative differences in the tumor vasculature. Results: Thirty-six eyes (18 cases of choroidal nevus and 18 cases of choroidal melanoma) from 36 consecutive patients were included in the study. Only cases located posterior to equator were included to enable performance of all tests. On optical coherence tomography angiography, choroidal nevus showed well-delimited margins (78%), hyperreflective choroid capillary vasculature (83%), fewer avascular areas (17%), and neovascular membrane in one case (6%). Choroidal melanoma showed imprecise margins (72%), hyporeflective choroidal capillary vasculature (72%), multiple avascular areas (78%), and choroidal vascular changes (e.g. thick vascular networks or vascular loops; 45%). Conclusion: Optical coherence tomography angiography can provide useful information for assessing and differentiating between choroidal nevi and small melanomas. Significant differences between these conditions were found for the pattern of reflectivity, and presence/absence of avascular zones and vascular anomalies, which could be helpful for supporting the diagnosis.