Spectrum of histological features in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) has become an Important entity globally, including in India and other Asian countries. Morphological evaluation of a liver biopsy is necessary for the diagnosis, staging and possibly management of this disease. However, the spectrum of changes in the liver, their evolution, Interrelationships and implications are incompletely understood. We aimed to study the spectrum of histological abnormalities in NAFLD.

The study material was drawn from a pool of 80 liver biopsies diagnosed in our laboratory as NAFLD, 67 retrieved retrospectively from our records and 13 obtained prospectively with complete clinical data. After comprehensive histological assessment, a detailed analysis was done of 32 of those categorized as definitive NAFLD on the basis of a dependable history of no alcohol Intake and seronegativity for hepatitis virus B and C Infections.

Fatty change was preferentially seen in acinar zones 2 and 3, more so in the former. Steatotic cells varied in size; some large ones were non-spherical. Steatosis alone was present in more than a quarter of the cases and steatosis along with inflammation was present in half. The magnitude of steatosis correlated with inflammation, while both these seemed to correlate with hepatocyte Injury and fibrosis.

A proportion of patients with NAFLD show only hepatic steatosis. An Increasing grade of steatosis is associated with greater Inflammation, hepatocyte injury and acinar fibrosis. Preferential involvement of acinar zone 2 by steatosis, the morphology of the steatotic cells, and nature and location of inflammation are important in the diagnosis of NAFLD and its differentiation from other causes of fatty liver.