[Incidentalomas].

A liver incidentaloma corresponds to a liver lesion detected during work-up of for unrelated pathology. The frequency of incidentalomas is directly related to the incidence of liver tumors in the general population. After detection of an incidental liver lesion, the goal is to assess if diagnosis can be made based on imaging features alone or if biopsy is required. As such, radiologists must be familiar with the imaging features of different types of liver lesions, irrespective of the imaging modality. US is useful to determine the number of lesions (single versus multiple) and the cystic or solid nature of each lesion. Cystic lesions are usually benign. Incidental solid liver lesions are typically benign, but detection of a malignant lesion, hepatocellular carcinoma and metastases, is possible. The most frequent benign incidental solid liver lesions are hemangioma, focal nodular hyperplasia and liver cell adenoma. Accurate imaging diagnosis may not always be achievable, and biopsy, percutaneous or surgical, may be required.