Nonalcoholic fatty liver disease (NAFLD): Diagnosis, pitfalls, and staging.

Nonalcoholic fatty liver disease (NAFLD) is increasingly prevalent and strongly associated with obesity, diabetes and the metabolic syndrome, not only in the Western societies, but also in most regions of the world in the 21st century. The spectrum of its histopathology ranges from steatosis to nonalcoholic steatohepatitis (NASH), with risk for progressive fibrosis that may lead to cirrhosis and hepatocellular carcinoma (HCC). Benign and malignant liver tumors have also been more frequently reported with the increasing prevalence of obesity and diabetes. This review addresses the pathology of NAFLD and NASH, and their diagnostic features, diagnostic pitfalls, grading and staging, and clinical correlation.