Fig 6. Photomicrograph from a retinoblastoma showing multiple Flexner-Wintersteiner rosettes. The halo-like cluster of cells in each rosette surrounds a nearly empty appearing central lumen containing fine cytoplasmic processes (H&E; original magnification 400x). Photomicrograph generously donated by Dr. Morton Smith, Ophthalmic Pathology, Washington University, St. Louis.