Lipofuscin is a brownish pigment left over from the breakdown and absorption of damaged blood cells.
Lipofuscin is found in heart muscle and smooth muscles and is also called the aging pigment.
Jogerst GJ, Wilbur JK. Care of the elderly. In: Rakel RE, ed. Textbook of Family Medicine. 7th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 7.