Evaluation of nonmalignant liver masses

Nonmalignant liver masses are increasingly being recognized with the widespread use of imaging modalities such as ultrasonography, computed tomography, and magnetic resonance imaging. The majority of these lesions are detected incidentally in asymptomatic patients. Based on the radiologic appearance, benign lesions can be categorized as solid or cystic, single or multiple, hypervascular or hypovascular. Based on histologic characteristics, they are classified as of hepatocellular, biliary, or mesenchymal origin. In the majority of patients, a proper diagnosis can be made based on these characteristics on imaging modalities alone. An invasive approach is seldom required. This review discusses the various characteristics of the most common benign liver lesions and recommends a practical approach.