noun, plural: lipofuscins
Lipofuscins are lipogenic pigments found chiefly in the smooth muscle cells, heart muscle cells, macrophages, parenchyma cells, interstitial cells, nerve cells, and ganglion cells. Their presence is associated with lysosomal degradation of the cell membrane. And high concentration of lipofuscins is noted in aged individuals. Organs that are going through senile atrophy have high levels of lipofuscins, which render the tissues brown.
Word origin: Greek lípos (fat) + Latin fusc(us) (dark, tawny)