By the limited information i gather from your querstion i understand that there is an interval developement of a hypodense lesion meaning that this wasnt present in the earlier scans. If the other clinical history which is not given in the query is of a maligancy it amy indicate secondaries in liver. Other wise it can be anything from an abscess to neoplasm. Possible choices for further assement include, Follow up or Histopathology.
Clinical correlation and consultation with ur physican will help as will other finding in the report.