Central element in liver masses, helpful, or pitfall?

A central element was first described in focal nodular hyperplasia (FNH) as a so-called “central scar,” and is normally associated with this entity. However, many other liver masses may present with a central element. Depending on its appearance, and the lesion itself, central elements can be essential, helpful, or confusing for diagnosis. Indeed, nodules that develop on liver vascular disorders, fibrolamellar hepatocellular carcinoma, large hemangioma, peripheral cholangiocarcinoma, or epithelioid hemangioenthelioma often present with a central element, thus increasing the level of diagnostic confidence when present. On the other hand, central elements are rare or atypical in liver metastases, hepatocellular adenoma, or hepatocellular carcinoma. In this setting, the presence of a central element can lead to a misdiagnosis. The description and details of the imaging features of these different central elements, especially on MRI, as well as a thorough evaluation of the entire lesion, can improve the diagnostic performance in these cases.