Liver histology essentials

Key points

1. Blood flows from the portal triad towards the central vein; bile flows the opposite way.
2. Zone 1 (periportal) is oxygen-rich and affected first in viral hepatitis and by ingested toxins such as iron.
3. Zone 3 (centrilobular) has the most cytochrome P450 and the least oxygen.
4. Ischaemic hepatitis, paracetamol toxicity and alcohol injure zone 3 first.
5. Kupffer cells are resident macrophages lining the sinusoids; stellate (Ito) cells store vitamin A and drive fibrosis.

Image guide

What to look for in each view of this topic.

1. Portal triad. Branch of the hepatic artery, portal vein and bile duct in connective tissue.
2. Central vein. Hepatocyte plates radiate towards the central vein, separated by sinusoids.
3. Zone 3 necrosis. Centrilobular necrosis after paracetamol overdose or shock liver.
4. Fatty change. Macrovesicular steatosis in alcohol-related and metabolic liver disease.
5. Mallory–Denk bodies. Eosinophilic cytoplasmic inclusions of damaged keratin filaments in alcoholic hepatitis.
6. Cirrhosis. Regenerative nodules surrounded by fibrous bands.