Perspectives on NASH Histology: Cellular Ballooning.

Interpretation of liver biopsy in NAFLD can be challenging to distinguish histological NASH from non-NASH fatty liver - a broad dichotomy which carries significant prognostic and therapeutic implications and underlies the utility of many non-invasive tests. There is usually a reasonable degree of inter-observer agreement for some key parameters like steatosis, inflammation and fibrosis staging. However, the assessment of cellular ballooning can be a stumbling block even for experienced observers. Below, we recount some aspects of the history of histological definitions in NASH and propose specific methods to more objectively identify cellular ballooning in routine biopsy assessments.