Histologic variation of grade and stage of non-alcoholic fatty liver disease in liver biopsies.

Background: Sampling error regarding disease grade and stage has been ascribed to needle liver biopsies in patients with chronic liver disease. Although several studies evaluating sampling error in liver biopsies exist, none have investigated this phenomenon in patients with non-alcoholic fatty liver disease (NAFLD). This study aims to determine the rate and extent of sampling error in liver biopsies obtained from patients undergoing Roux-en-Y gastric bypass (RYGBP) surgery for morbid obesity.