Xanthelasma consists of lipid filled macrophages, called foam cells
The foam cells contain clear cytoplasm in clusters, with a few lymphocytes.
There is usually minimal fibrosis in early lesions.
Eruptive xanthomas occur as small yellow to red papules in crops, primarily over the extensor surfaces of the arms and legs. Primary disorders of lipid metabolism, in association with diabetes, pancreatitis, or nephrotic syndrome, underlie their formation. Certain drugs (steroids, estrogens, etc) may also cause xanthomas.