It is not uncommon to see a granuloma on a liver biopsy. Granulomatous disease carries a broad diferential diagnosis. You should consider sarcoidosis, primary biliary cirrhosis, drug effect, tuberculosis (if necrotizing), and schistosomiasis. Furthermore, it could be idiopathic and completely benign; that would be a diagnosis of exclusion.
Notice in the histologic specimen above the well-circumscribed collection of cellular debris, containing some inflammatory cells (neutrophils are the multi-lobed cells), bile ducts, necrotic tissue and extracellular matrix.