Miyata, Sukata, Kushida et al. 201 with an uneven distribution among the lobes, corresponding to the gross lesion (Figs. 2, 3). The pigmentation was strongest around periportal areas. The staining intensity was weaker in midzonal areas, and very weak to absent in c e n tr i l o bu l a r he p a t oc y te s . T h u s , t h e r e w a s a c l e a r diminishing periportal-to-centrilobular gradient. Regarding the distribution of the pigments in the cell, those were aggregating close to bile canaliculi. Berlin Blue staining revealed conclusive evidence that the pigments were hemosiderin. No degeneration or necrotic changes were observed. Kupffer cells did not exhibit appreciable accumulation of iron. Transmission electron microscopy revealed cytosolic ferritin and pericanalicular lysosomes, or siderosomes, in periportal hepatocytes (Fig. 4). Many single membrane limited bodies filled with electron opaque aggregates were Fig. 1. A liver preserved in formalin solution. Note the reddish brown coloration. Fig. 2. The liver tissue shows uneven positive staining with Berlin Blue. a. H.E staining, b. Berlin Blue staining. Fig. 3. Very fine yellowish brown pigments showing a positive reaction with Berlin Blue stain are apparent in hepatocytes. The pigments in the cytoplasm are close to bile canaliculi, with a diminishing periportal-to-centrilobular gradient. a, c. H.E stain. b, d. Berlin Blue stain.