It's a medical term. It consists of the accumulation of fats in the inner layer of veins or arteries.
ateroma-refers to lacumulation, in the inner wall of large arteries, of lipid plaques that evolve into sclerosis and calcination-
ATHEROMA: Cyst Sebaceous.
ATEROMA:CUMULO OR STACKING OF FAT INSIDE AN ARTERY... POLYP, OR FATTY, GREASY, FAT NODULE.