To the Editor.
—We read with deep interest the paper of Joan Mullaney, MD, on "Retinoblastoma With DNA Precipitation" (Arch Ophthal82:454-456, 1969). Unaware of the previous works of Dr. Mullaney on this subject, we communicated on the same DNA deposition in certain structures in retinoblastoma eyeballs based on our observations in ten cases.1 We might mention here that we have observed this peculiar basophilia not only in the walls of the tumor blood vessels but also on the lens capsule, on the internal limiting membrane of the retina, and in membrane-like structures in the vitreous cavity (Figure). We did not observe this tinctorial reaction, however, on the walls of iris blood vessels. The histochemical reactions utilized in this work included Von Kossa and alizarin red for calcium; Verhoeff's and Weigert's stains for elastic fibers, PAS, the Feulgen reaction before and after DNA-ase pretreatment of the sections, tricholacetic
Bernardino V, Salceda SR. DNA PRECIPITATION. Arch Ophthalmol. 1970;84(4):547. doi:10.1001/archopht.1970.00990040549031