pineal glandListen to pronunciation(PIH-nee-ul ...)A tiny organ in the cerebrum that produces melatonin. Also called pineal body and pineal organ.Enlarge this image in new windowAnatomy of the inside of the brain, showing the pineal and pituitary glands, optic nerve, ventricles (with cerebrospinal fluid shown in blue), and other parts of the brain.Search NCI's Dictionary of Cancer TermsStarts withContainsBrowse:ABCDEFGHIJKLMNOPQRSTUVWXYZ#