Thermal transition studies of a mature xanthelasma by differential scanning calorimetry.

A large xanthelasma which had been present for at least 5 years was removed surgically from a normolipaemic female age 54 years, and examined in the fresh state by differential scanning calorimetry. Thermal transitions recorded over the range 30-40 degrees C suggest that the lipid present, predominantly esterified cholesterol, is not bound to protein or other tissue components, and that the chronicity of mature xanthelasmata as with ectopic lipid deposits at other sites is enhanced by chemical modification of lipid and effects on component phase behaviour, which are significant at local skin temperature.