Peripapillary subretinal neovascularization in retinoblastoma

Background Peripapillary subretinal neovascularization (PSRNV) is a rare type of choroidal neovascularization. Herein we report a case of retinoblastoma complicating PSRNV, and discuss the histopathological findings. Methods A 1-year-old male underwent enucleation of his right eyeball based on the clinical diagnosis of bilateral retinoblastoma after chemotherapy. Results There was a mass arising from the retina showing highly calcified and necrotic retinoblastoma. The peripapillary region revealed neovascular membrane extending from the optic nerve head to the subretinal space. The membrane included retinal pigment epithelial (RPE) cells and glial cells, as well as endothelial cells. Immunohistochemistry revealed cytokeratin 18-positive RPE cells situated beneath glial fibrillary acidic protein-positive glial cells and their processes. The neovascular membrane did not have a connection with vessels arising from the optic nerve head. There were multiple mound foci made up of proliferated RPE cells in the globe. Conclusion These results suggest that migration of RPE cells and glial cells plays a crucial role in the pathogenesis of PSRNV, which might be directly or indirectly mediated by retinoblastoma.