Histopathology of nonalcoholic fatty liver disease

Table 2 Nonalcoholic steatohepatitis Clinical Research Network system for scoring activity and fibrosis in nonalcoholic fatty liver disease (modified from[54])

Steatosis grade (S)	Lobular inflammationa (L)	Hepatocyte ballooning (B)
0: < 5%	0: None	0: None
1: 5%-33%	1: < 2	1: Few ballooned cells
2: 34%-66%	2: 2-4	2: Many ballooned cells
3: > 66%	3: > 4

^aCounted in 20 × fields. Nonalcoholic fatty liver disease Activity Score: S + L + B (range 0-8). Stage of fibrosis (Fibrosis score): 0: None; 1: 1a, mild, zone 3 perisinusoidal fibrosis, 1b, moderate, zone 3 perisinusoidal fibrosis, 1c, portal/periportal fibrosis only; 2: Zone 3 perisinusoidal fibrosis and portal/periportal fibrosis; 3: Bridging fibrosis; 4: Cirrhosis, probable or definite.