Retinoblastomas contain various basophilic deposits which have always been considered to be composed of calcium only. A study of a series of retinoblastomas shows that such deposits occurring in vascular walls, and occasionally free in the stroma in some cases, are in fact, due to the deposition of deoxyribonucleic acid. The precipitation of this substance does not appear to parallel the degree of necrosis or calcification or both, but it is suggested that tumors containing well-formed rosettes have virtually no significantly free DNA.
Mullaney J. Retinoblastomas With DNA Precipitation. Arch Ophthalmol. 1969;82(4):454-456. doi:10.1001/archopht.1969.00990020456005