Subcutaneous fat necrosis of the newborn: Light and electron microscopic studies.

Specimens from two cases of subcutaneous fat necrosis of the newborn were studied by light and electron microscopy. Crystallization of the fat cell started with clearing of the central fat droplet, followed by the appearance of cylindrical crystals. The fat crystals were phagocytosed by cytoplasmic projections of macrophages as well as by foreign body giant cells. Calcium deposits were demonstrated within the central fat droplet of the degenerated fat cell of Case 2.