Table 1. NASC/CRN grading criteria.

NASH diagnosis correlates with steatosis, related chronic steatohepatitis, and fibrosis. Biopsies of grade ≥5 were diagnosed as NASH; those of grade <3 were diagnosed as “not NASH.”

Grade:	Criteria:
Steatosis grade:	0 <5%;
	1 - 5–33%;
	2 - 34–66%;
	3 >66%
Steatosis distribution:	centrilobular vs diffuse
Lobular inflammation:	0 - none;
	1 < 2 foci/20x field;
	2 - 2–4 foci/20x field;
	3 > 4 foci/20x field
Hepatocellular ballooning:	0 - none;
	1 - mild, few;
	2 - moderate-marked, many
Portal inflammation:	0 - none;
	1 - mild,
	2 > mild,
	3 - severe
Fibrosis (Trichrome stain):	0 - none
	1a - mild zone 3 perisinusoidal fibrosis, requires trichrome stain to identify
	1b - moderate zone 3 perisinusoidal fibrosis, also noticeable by H&E
	1c - portal fibrosis only;
	2 - zone 3 perisinusoidal fibrosis and periportal fibrosis
	3 - bridging fibrosis
	4 - cirrhosis