Recall that blood flows into the liver via the hepatic veins (in the portal triad) and out of the liver via the central veins in the lobules.
Alcohol coming from the gut first makes contact with the hepatocytes nearest the portal triad. These liver cells, therefore, will be affected first by the toxicity of alcohol. The fibrosis (in blue in this trichrome stain) is coming "from the outside in" with respect to the lobule. At this stage, the lobules themselves are spared.
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As the heart fails, blood is backed up in the venous system. The central veins (arrow), you recall, eventually empty into the inferior vena cava. Since the heart is "backed up," you can see the red blood pooling near the central vein of some lobules. In this process, fibrosis occurs "from the inside out."
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The Hepatitis B virus is extremely contagious and causes widespread necrosis of the liver. The destruction encompasses both the lobules and the interstitium making this tissue almost unrecognizable. Fortunately, you received the HBV vaccine when you started medical school. And since 1991, it is recommended that all newborns receive it as well.
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