Piecemeal necrosis on liver biopsy is a feature of -
Pathological features of chronic active hepatitis 

There is active continuous necrosis of liver cells leading to following features.
Portal tracts show severe chronic inflammation with inflammatory cells extending into the liver lobules disrupting the limiting plate of hepatocytes.
Piecemeal necrosis   
Portal fibrosis
Bridging necrosis
Interface hepatitis

Pathological features of chronic persistent hepatitis (Chronic minimal hepatitis) 

Portal chronic inflammation is mild and restricted to the portal triads, there is no disruption of the limiting plates.
Little or no necrosis
Minimal fibrosis.
Alcoholic hepatitis
Indian childhood cirrhosis
Chronic active hepatitis
Primary alcoholic cirrhosis