Sinus histiocytosis massive lymphadenopathy syndrome: histogenesis of the hepatic lesion

Sinus histiocytosis massive lymphadenopathy (SHML) syndrome with hepatic involvement, occurring in a seven-year-old black female, is reported. Morphologic characterization of the hepatic lesion is accomplished utilizing conventional light, fluorescent and electron microscopy, and histochemical techniques and by comparing and contrasting the findings with those in cases of familial erythrophagocytic lymphohistiocytosis (FEL) and virus-associated hemophagocytic syndrome (VAHS). The histiocytic proliferation in the liver in SHML differs by showing: (a) an intralobular distribution with portal sparing; (b) marked steatosis; and (c) lipofuscinosis. The aforesaid intralobular distribution and the accompanying hypertrophy and hyperplasia of Kupffer cells, as well as commonalities of steatosis and lipofuscinosis, and, to a lesser extent, erythrophagocytosis and siderosis, suggest a histogenesis from Kupffer cells. The histochemical finding of fatty acid peroxides and both fluorescent microscopic and histochemical evidence of lipofuscin inclusions, a by-product of lipid peroxidation, in Kupffer cells provide at least a theoretical basis for both erythrophagocytosis and proliferation eventuating in intralobular histiocytosis.