Size matters ▸

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Liver biopsy has remained the “gold standard” to assess the severity of liver injury despite studies showing significant intra and interobserver variability in the evaluation of inflammation (grade) and fibrosis (stage). Serial biopsies have been used extensively to monitor the progress of disease and response to therapy.

Colloredo et al have highlighted yet another variable that affects the estimation of disease severity using liver biopsies. From patients with chronic hepatitis B and C, authors selected 161 liver biopsies, each ⩾3 cm long and 1.4 mm wide, and used the “Ishak scale” to assess the severity of disease. The biopsies were then made shorter (by covering with opaque paper) and/or thinner (by viewing through a modified micrometer eyepiece) and blindly re-read by the same pathologist. As the biopsies shortened, more were graded as having mild disease (50% in ⩾3 cm, 60% in 1.5 cm, and 87% in 1 cm specimens; p<0.001). Cases staged as having mild fibrosis increased in the shorter specimens (59% in ⩾3 cm, 68% in 1.5 cm, and 80% in 1 cm specimens; p<0.001). Both grade and stage were underscored in thinner samples regardless of their length.

In a way, this …