steatosis

This term is a precise medical descriptor used primarily in pathology and clinical diagnostics. It describes a cellular-level change where fat droplets displace the normal contents of a cell, creating a characteristic vacuolated appearance under a microscope. While it can occur in various organs, it is most frequently associated with the liver, where it serves as a precursor to more severe inflammatory conditions like steatohepatitis.

As a technical medical noun, it is treated as an uncountable mass noun. It refers to the pathological state or process of fatty infiltration rather than individual instances of fat. Consequently, it does not take a plural form in standard clinical usage and is typically modified by adjectives describing the severity or location, such as "mild" or "hepatic."