Spectrum: Steatosis ↔ Steatohepatitis (NASH) → Fibrose → Zirrhose

Etiology:- Individuals with metabolic syndrome (3 of the following 5: obesity, hypertension, diabetes, hypertriglyceridemia, hyperlipidemia)- Medication (amiodarone, glucocorticoids, estrogen, antiretroviral drugs)

Pathophysiology:↑ Insulin resistance- ↑ Peripheral lipolysis- ↑ Triglyceride synthesis- ↑ Hepatic uptake of fatty acids

Histopathology:- Steatosis: White vacuoles- Steatohepatitis: Mallory-denk bodies (tangles of intermediate filaments), neutrophils- Chronic steatohepatitis: Stellate cells lay down fibrotic tissue → fibrosis & cirrhosis

Macroscopic:- Steatosis: Large, soft, yellow, greasy

Diagnosis:- ↑ Transaminases (AST/ALT ratio < 1)- Imaging studies: US, CT, MRI- Biopsy: Liver with >5% fat content is abnormal