Cysts and haemangiomas, which are frequent benign tumours of the liver, must be separated from hepatic adenoma and focal nodular hyperplasia. The former are usually diagnosed by ultrasonography and/or computed tomography (CT), and they exceptionally require surgery. The latter, much rarer, are similar in that both occur in young women and have the same imaging characteristics: CT does not always show the sign that confirms the diagnosis of focal nodular hyperplasia (i.e. a central "scar" vascularized at CT-angiography); scintigraphy would provide the diagnosis, but it is at fault in 30 to 40% of the cases. Excluding a malignant tumour (hepatocellular carcinoma or fibrolamellar hepatocarcinoma) is sometimes difficult. Often more than a certainty, it is a collection of convergent clinical and radiological data that leads to the correct diagnosis.