"Cornflake nevoid" lesions, mimicking choroidal lesions of neurofibromatosis 1, in the absence of neurofibromatosis 1: An imaging-based hypothesis

Abstract

Whitish hypermelanocytic flake-like lesions on scanning laser ophthalmoscopy (SLO) multicolor posterior pole imaging (PPI) can correspond to several conditions, including simple nevi or shallow choroidal melanomas, paraneoplastic fundus lesions like bilateral diffuse uveal melanocytic proliferation, or choroidal melanocytic lesions found in neurofibromatosis type 1 (NF1). We report three cases with unilateral flake-shaped choroidal lesions on SLO multicolor PPI, similar to choroidal NF1 lesions, monitored their evolution and analyzed their potential nature using multimodal imaging including SLO multicolor and classical PPI, infrared autofluorescence (IRAF), spectral-domain-optical coherence tomography (SD-OCT), enhanced-depth imaging-OCT (EDI-OCT), OCT-angiography as well as fluorescein angiography, and indocyanine green angiography (ICGA). Two oncologic patients and one healthy patient presented unilateral whitish cornflake-shaped lesions on SLO multicolor and IRAF PPI, faintly or not visible on fundus photography, hypofluorescent on the intermediate-phase ICGA, but isofluorescent on the late-phase ICGA corresponding to hyperreflective areas in the choroid immediately under the retinal pigment epithelium on SD-OCT. The lesions were nonevolutive. Multimodal imaging determined that these "nevoid" lesions were melanocytic but could not be assimilated to classical nevi, having a looser structure that allowed some indocyanine green impregnation explaining the isofluorescence on the late-phase ICGA. The lesions were similar to those described in NF1 cases and were unrelated to the oncologic status.

Keywords: Choroidal neurofibromatosis 1; indocyanine green angiography; near-infrared image; scanning laser ophthalmoscope multicolor photographs.