If a ct scan shows an enlarged liver up to 20cm demonstrating a stable too small to characterize hepatic dome hypodensity what does this mean?

The are numerous: causes of liver enlargement including infection/inflammation, fatty infiltration, metabolic disturbances, cardiac dysfunction, and deposition/storage diseases. Not enough info to venture a guess here. As far as the "too small to characterize" lesion, the vast majority of these incidental lesions are benign cysts or hemangiomas that require no treatment.