Molecular pathologic interpretation of new retinoblastoma rosettes.

Newly described retinoblastoma (RB) rosettes have various kinds of pathological significance. Some of their characteristics have been revealed in this immunohistochemistry study. Five paraffin-embedded eyeballs with RB and new rosettes were studied for neuron-specific enolase (NSE), p53, p16, BAX, c-Myc, glial fibrillary acidic protein, synaptophysin, and chromogranin. They were compared and interpreted using control specimens. NSE, P53, and P16 were significantly expressed in the cells of the new rosettes. The presence of new RB rosettes that mostly have histopathological high-risk factors and p53 positivity may be a strong marker of poor prognosis of RB.