Fetal Niemann-Pick disease type C: ultrastructural and lipid findings in liver and spleen.

We present the first ultrastructural study of liver and spleen from a 20-week fetus with Niemann-Pick disease type C in correlation with lipid studies of these tissues. The lipid storage pattern was characteristic of the disease and although the distribution of the lipid storage was similar to that of affected children, ultrastructural studies emphasized that many inclusions were qualitatively different. These are discussed. Concomitant with this complex lipid storage, ultrastructural evidence of cholestasis was observed and the early hyperplasia of pericanalicular microfilaments leads us to question the presence of a toxic metabolite which might induce cholestasis by acting upon microfilaments.