Role of liver biopsy in nonalcoholic fatty liver disease

Table 3 Nonalcoholic steatohepatitis clinical research network nonalcoholic fatty liver disease scoring system

Steatosis grade	Lobular inflammation	Liver cell ballooning
0: < 5%	0: No foci	0: None
1: 5%-33%	1: < 2 foci per 200 × field	1: Few ballooned hepatocytes
2: 34%-66%	2: 2-4 foci per 200 × field	2: Many ballooned hepatocytes
3: > 66%	3: > 4 foci per 200 × field

Reproduced with permission[65]. Nonalcoholic fatty liver disease activity score (NAS): Steatosis + inflammation + ballooning. Fibrosis, 0: None; 1: Perisinusoidal or periportal; 1A: Mild, zone 3 perisinusoidal; 1B: Moderate, zone 3 perisinusoidal; 1C: Portal, periportal; 2: Perisinusoidal and portal/periportal; 3: Bridging fibrosis; 4: Cirrhosis.