DNA coating of blood vessels in retinoblastomas.

Hematoxylin staining of vascular walls has so far been considered to be a feature of oat-cell carcinomas exclusively. The occurrence of similar blue staining of not only vascular but other membrane structures of the eye in retinoblastomas is reported here. The blue-staining material in retinoblastoma and the oat-cell tumor is DNA, presumably released from the necrotic tumor nuclei.