Pathology of an eye with enucleated retinoblastoma showing optic nerve invasion. The hematoxylin-eosin photomicrograph shows the posterior displacement of the lamina cribrosa by a compact blue tumor. Cords of tumor cells are intermingled with the retrobulbar nerve tissue. The central retinal vessels are surrounded by the invading tumor. Inset: higher-power magnification showing details of the central retinal vein surrounded by packed tumor cells. Blood flow velocity in monocular retinoblastoma assessed by color Doppler. Bonanomi MT, Saito OC, de Lima PP, Bonanomi RC, Chammas MC - Clinics (São Paulo, Brazil) (2015). Not Altered. CC.