MULTIMODAL IMAGING OF CRB1 RETINITIS PIGMENTOSA WITH A PERIPHERAL RETINAL TUMOR

To report the multimodal imaging findings of a patient with gene- crumbs 1 -associated retinitis pigmentosa (RP) characterized by preservation of para-arteriolar retinal pigment epithelium and a peripheral retinal tumor.A 27-year-old woman was referred to our center because of progressive decreased vision in both eyes with a diagnosis of gene- crumbs 1 -associated RP. Fundus examination was remarkable for attenuated retinal vessels and bone spicule migration that was bilateral and symmetric. In addition, an elevated yellow-white mass with dilated retinal vessels was noted in the superotemporal midperiphery of the retina in the left eye without any associated exudation.Diffuse retinal pigment epithelium mottling was present but spared the area along the retinal arterioles. Swept-source optical coherence tomography showed diffuse outer retinal atrophy. Optical coherence tomography angiography of the peripheral lesion illustrated extensive vascularity and a possible retinal feeder vessel communicating with the tumor at its inferior margin. The phenotype of the lesion showed overlap with a vasoproliferative tumor or an astrocytic hamartoma. Over a period of 5 years of follow-up, the peripheral tumor was unchanged. No significant progression of the peripheral retinal degeneration was evidenced by autofluorescent imaging over this time period although the central acuity continued to decrease.Gene- crumbs 1 -associated RP may be characterized by preservation of the para-arteriolar retinal pigment epithelium and slow progression and may also feature a benign peripheral retinal tumor.