LIPID STORAGE UNDER ABNORMAL CONDITIONS 699 



of blood cholesterol is doubled or trebled, while there is a ten- to sixty-fold 

 increase in the neutral fat concentration in the serum. 917 



Peters and Van Slyke 549 are of the opinion that the designation, "sec- 

 ondary xanthomatosis," should be confined to cases in which the xan- 

 thomatosis is secondary to another disease characterized by a hyperlipemia, 

 such as diabetes. The following sub-groups are listed in this category, by 

 Thannhauser and Schmidt 922 : (i) idiopathic or familial hyperlipemia with 

 hepatosplenomegaly and secondary xanthoma ; (2) secondary xanthomatosis 

 due to diabetic hyperlipemia; (3) hyperlipemia with secondary xanthoma- 

 tosis occurring in chronic pancreatitis; (4) hyperlipemia in glycogen storage 

 disease; and (5) hyperlipemia in lipoid nephrosis. 



(c) Localized Xanthoma Formation in Inflamed Tissue and in True 

 Tumors. In addition to primary and secondary xanthomatosis, which are 

 generalized types of the disease, xanthoma formation may originate in 

 localized areas. The first division of this group are the xanthoma cells in 

 inflamed tissue. This is subdivided as follows: (1) inflamed tissue showing 

 xanthoma cells ; (2) inflammatory xanthoma of the breast ; (3) xanthoma 

 cells in osteitis fibrosa cystica disseminata (fibrous dysplasia) ; (4) xanthoma- 

 tous transformation of the mesentery, intestinal lipodystrophy of Whipple ; 

 and (5) xantholipoma. 



The second division is made up of xanthoma cells in tumors. This 

 category includes the following: (1) nevoxanthoendotheliomas; (2) 

 xanthomatous polycystic lymphangiomas; (3) single xanthomatous giant- 

 cell tumors; and (4) epithelial tumors with xanthoma cells. 



A third division, comprising xanthoma cells in other conditions, in- 

 cludes only two sub-groups, viz., (1) lipoid proteinosis and (2) necrobiosis 

 lipoidica diabeticorum. 



b. Niemann-Pick's Disease (Reticular and Histiocytic Sphingomyelino- 

 sis). Niemann 928 first discovered this disease in 1914. Thirteen years 

 later, Pick 929 differentiated the syndrome from that of Gaucher's disease. 

 Comprehensive studies of the disease have been reported by Baumann, 

 Klenk, and Scheidegger, 930 and by Thannhauser. 917 



The nature of the chemical disturbance in Niemann-Pick's syndrome was 

 clarified by Klenk. 931,932 He discovered that the lipid present in the large 

 pale cells was the phospholipid, sphingomyelin. These sphingomyelin- 



928 A. Niemann, Jahrb. Kinderheilk., 79, 1-10 (1914). 



929 L. Pick, Med. Klin. {Munich), 23, 1483-1488 (1927). 



930 T. Baumann, E. Klenk, and S. Scheidegger, Ergeb. allgem. Pathol, u. palhol. Anat., 

 SO, 183-323 (1936). 



9 " E. Klenk, Z. physiol. Chem., 235, 24-36 (1935). 

 932 E. Klenk, Z. physiol. Chem., 229, 151-156 (1934). 



