HISTOPATHOLOGY OF THE LIVER IN HISTIOCYTOSIS SYNDROMES

Liver biopsies were studied in 47 cases representing various histiocyt osis syndromes. These included 32 cases of hemophagocytic syndrome, 11 cases of langerhans cell histiocytosis (LCH), and 4 cases of other hi stiocytic disorders. All cases of hemophagocytic syndrome, except one with cytomegalovirus infection, displayed portal lymphohistiocytic inf iltrates dominated by T lymphocytes. Activation of the hepatic mononuc lear phagocytic system (MPS), evidence by enlarged von Kupffer cells, some of which were hemophagocytic, was seen in 28 cases of hemophagocy tic syndrome. Endothelial enlargement, minor degrees of hepatocellular degeneration, and steatosis were also noted. Ten of the 11 cases of L CH also showed activation of the MPS. It was the only lesion in two bi opsies. Seven cases demonstrated nonspecific ''traiditis.'' In three t his was associated with cholangiocentric and random acinar histiocytic lesions. Evidence of activation of the MPS was also observed in both cases of Rosoai-Dorfman disease and was accompanied by acinar histiocy tic lesions in one and triaditis in the other. Likewise, both cases of juvenile xanthogranuloma showed activation of the MPS and focal granu lomatous lesions. It is concluded that activation of the MPS is a comm on feature of liver disease in histiocytosis syndromes and that hepati c enlargement may be the result of this process instead of, or in addi tion to, the liver lesions known to be featured in these disorders. He patic lesions of the various histiocytosis syndromes resemble typical lesions in other sites and, in some instances, are accompanied by nons pecific changes. These nonspecific changes may occur in the absence of lesions that are diagnositic or typical of the particular histiocytos is syndrome. The location and character of hepatic lesions are importa nt factors in the significance of liver involvement.