[Ultramicroscopic studies in retinoblastoma]

Were examined three cases with undifferentiated retinoblastoma. Were effected cross sections on the samples, remarking tumoral cells with normal aspect interspersed with tumoral necrosis cells. Tumoral cells of the undifferentiated retinoblastoma has low size and a poor cytoplasmic with a big nucleus that occupies nearly the whole cell; the ratio nucleus/cytoplasmic is increased. The cells are uni- or binucleus and the nucleus is monstrous deep invagination of the cover nucleus. Cytoplasmic has poor organelles and mitochondria are swelling following a high degree of hypoxia. Also tumoral cells on remark nontumoral cells (melanocyte).