[Anatomicopathological studies in retinoblastoma]

For a fifteen-years period it has been examined fourteen cases with retinoblastoma, twelve of them have been undifferentiated forms and two cases differentiated forms in rosette, in undifferentiated retinoblastoma has been observed low size cells with poor cytoplasm and big nucleus that occupied near the whole cell; the nucleus to cytoplasm ratio is increased. The cellular density is irregular and most important perivascular. The tumoral parenchyma is condensed in perivascular areas, the tumoral stroma is poor, amorphous or mucinous. The necrosis areas are frequently but very import out in undifferentiated retinoblastoma. The tumoral vascularity is increased. In some cases occur melanin pigment that belong to the pigment epithelium without the existence of tumoral proliferation.