A histochemical and biochemical study of a liposarcoma with several aspects on the development of fat synthesis.

The report describes a case of lipocytic and lipoblastic liposarcoma, morphologically to be classified as well-differentiated. A considerable number of liopoblastic areas with the mass of the tumour proper which contain large amounts of glycogen are interspersed. These immature lipocytes reproduce the histogenesis of normal white fat. The quantity of glycogen-storing lipoblastic cells nearly equals that of the fat-storing lipocytic cells. Acid mucopolysaccharides are seen in only small areas of tumour. Histochemical staining as well as biochemical investigations, show that the majority of tumour fat consists of triglycerides, followed by cholesterol esters. There are also small amounts of free cholesterol, phospholipids, free fatty acids and a further fraction, which seems to be a glycerol ether. There exist differences in the quantitative content of cholesterol, phospholipids and triglycerides of tumour fat compared to normal fat. No significant difference exists between the fatty acids in tumour fat and those in normal fat outside of the tumour.