Mallory-Denk Bodies (MDB) are important as investigators, suggesting MDB as an indicator of the histologic severity of chronic hepatitis, causes of which include hepatitis C, primary biliary cirrhosis (PBC), and nonalcoholic fatty liver disease (NAFLD). Matteoni et al scored MDB in patients with NAFLD as none, rare and many, and reported that MDB plays a prominent role in this classification scheme in an earlier classification system. In this study, we evaluated 258 patients with chronic hepatitis due to metabolic, autoimmune and viral etiologies. Liver biopsy samples were evaluated with hematoxylin and eosin, periodic acid-Schiff-diastase, Gordon and Sweet's reticulin, Masson's trichrome, and iron stains. Both staging and grading were performed. Additionally, MDB were evaluated and discussed for each disease. We examined patients with nonalcoholic steatohepatitis (NASH; 50 patients), alcoholic hepatitis (10 patients), PBC (50 patients), Wilson disease (WD; 20 patients), hepatitis B (50 patients), hepatitis C (50 patients) and hepatocellular carcinoma (HCC; 30 patients). Frequency of MDB was as follows; NASH: 10 patients with mild in 60% and moderate in 40% and observed in every stage of the disease and frequently seen in zone 3. PBC: 11 patients with mild in 10%, moderate in 70%, and cirrhosis in 20%, and frequently seen in zone 1. WD: 16 patients with moderate and severe in 60% and cirrhosis in 40% and frequently seen in zone 1. Hep B: 3 patients with mild in 66% and severe in 34%. Hep C: 7 patients with mild in 40% and moderate in 60% and observed in every stage. HCC: 3 patients with hep B in 2 patients. We found that there is no relationship between MDB and any form of chronic hepatitis regarding histologic severity such as alcoholic steatohepatitis and NAFLD and variable zone distribution by etiology. (C) 2011 Baishideng. All rights reserved.