Yellowish white precipitates are sometimes observed clinically in the subretinal area of the retinal detachments. We investigated retinal detachments observed in a 47-year-old man associated with choroidal malignant melanoma and in a 1-year-old girl with retinoblastoma. Yellowish white precipitates were foam cells located around degenerated outer and inner segments of photoreceptor cells. They were more abundantly present associated with malignant melanoma than with retinoblastoma. They exhibited abundant lipid droplets, abundant lysosomes with phagocytosed materials including inner segments, fibrin, melanin and lipofuscin, abundant glycogen particles, indented nuclei, and cytoplasmic processes without intercellular junctional apparatus. They appeared to be macrophages.