Elements from human diagnostics | Score | Type/localization |
---|---|---|
Steatosis (NAS) | 0: < 5% 1: 5–33% 2: > 33–66% 3: > 66% | Macrovesicular, microvesicular or mixed Zone 1, 2, 3 |
Fibrosis (NAS) | 0: None 1: Perisinusoidal or periportal 2: Perisinusoidal and portal/periportal 3: Bridging 4: Cirrhosis | Subgroups of score 1: 1A: Mild, zone 3, perisinusoidal 1B: Moderate, zone 3, perisinusoidal 1C: Portal/periportal |
Inflammatory foci per 200× field, mean of 3 fields (NAS) | 0: 0 1: < 2 2: 2–4 3: > 4 | Lobular or portal |
Hepatocellular ballooning | 0: None 1: Few balloon cells 2: Many cells/prominent ballooning | Hydropic degeneration |
Mallory–Denk bodies | 0: None to rare 1: Many |
Other elements | Score | Localization |
---|---|---|
Cytoplasmic alterations | 0: − 1: + 2: ++ 3: +++ | Zone 1, 2, 3 |
PAS positive staining | 0: − 1: + 2: ++ 3: +++ | Zone 1, 2, 3 |