Table 2a Grading for NAFLDa

From: Pathology of fatty liver disease

NAS

Steatosis b

Ballooning

Inflammation, lobular c

0

<5% (0)

None (0)

None (0)

3

5–33% (1)

Rare or few (1)

1–2 foci per 20 × field (1)

6

34–66% (2)

Many (2)

2–4 foci/20 × field (2)

8

>66% (3)

Many (2)

>4 foci/20 × field (3)

  1. NAS: NAFLD activity score.
  2. aThe number in parentheses is the NAS score for each histologic feature. This is an example of how the composite NAS is derived for any case of NAFLD; in any case, the combinations of lesions may differ, and thus, the NAS would also.
  3. bSteatosis estimated by percent of fat in hepatocytes by examination at 4 × and 10 × .
  4. cIncludes all types of inflammatory cells in clusters in lobule (mononuclears, neutrophils, eosinophils).
Back to article page