Table 1.
Nonalcoholic steato-hepatitis Clinical Research Network Scoring System (adapted from ref. [3])
| Item | Definition | Score/code | |
| Steatosis | |||
| Grade | Low-to medium-power evaluation of parenchymal involvement by steatosis | ||
| < 5% | 0 | ||
| 5%-33% | 1 | ||
| > 33%-66% | 2 | ||
| > 66% | 3 | ||
| Location | Predominant distribution pattern | ||
| Zone 3 | 0 | ||
| Zone 1 | 1 | ||
| Azonal | 2 | ||
| Panacinar | 3 | ||
| Microvesicular steatosis | Contiguous patches | ||
| Not present | 0 | ||
| Present | 1 | ||
| Fibrosis | |||
| Stage | None | 0 | |
| Perisinusoidal or periportal | 1 | ||
| Mild, zone 3, perisinusoidal | 1A | ||
| Moderate, zone 3, perisinusoidal | 1B | ||
| Portal/periportal | 1C | ||
| Perisinusoidal and portal/periportal | 2 | ||
| Bridging fibrosis | 3 | ||
| Cirrhosis | 4 | ||
| Inflammation | |||
| Lobular inflammation | Overall assessment of all inflammatory foci | ||
| No foci | 0 | ||
| < 2 foci per 200 × field | 1 | ||
| 2-4 foci per 200 × field | 2 | ||
| > 4 foci per 200 × field | 3 | ||
| Microgranulomas | Small aggregates of macrophages | ||
| Absent | 0 | ||
| Present | 1 | ||
| Large lipogranulomas | Usually in portal areas or adjacent to central veins | ||
| Absent | 0 | ||
| Present | 1 | ||
| Portal inflammation | Assessed from low magnification | ||
| None to minimal | 0 | ||
| Greater than minimal | 1 | ||
| Liver cell injury | |||
| Ballooning | None | 0 | |
| Few balloon cells | 1 | ||
| Many cells/prominent ballooning | 2 | ||
| Acidophil bodies | None to rare | 0 | |
| Many | 1 | ||
| Pigmented macrophages | None to rare | 0 | |
| Many | 1 | ||
| Megamitochondria | None to rare | 0 | |
| Many | 1 | ||
| Other findings | |||
| Mallory's hyaline | Visible on routine stains | ||
| None to rare | 0 | ||
| Many | 1 | ||
| Glycogenated nuclei | Contiguous patches | ||
| None to rare | 0 | ||
| Many | 1 | ||