Imaging findings of unusual hepatic tumors: expanding the differential diagnosis.

Abstract

Radiol Bras. 2014 Set/Out;47(5):IX–X In the last two decades, the sizeable increase in the number of imaging examinations performed for various clinical indications has led to a profound change in the way several lesions in different organs and clinical situations are diagnosed. Those changes cover a range of impacts on the management of such lesions and on the approach to such cases which can or may not be clinically significant. That is to say, a great increase in incidentally found lesions, including clinically insignificant and subclinical lesions, has allowed radiologists to increase even more their already intense contribution to the understanding of the natural history of several of such lesions by means of providing an early diagnosis as well as by delivering imaging follow-up of some lesions. In this context, we have also witnessed an intense development of histopathological analysis methods, including modern techniques of molecular biology. Specifically in the case of focal hepatic lesions, there was a significant diagnostic improvement, with increased accuracy of imaging methods in the evaluation of the most frequent lesions such as hemangioma, focal nodular hyperplasia, adenoma, and especially hepatocellular carcinoma. The accumulated solid evidence-based knowledge has radically and positively changed the management of patients with the definition of their typical presentations. For example, currently, histopathological confirmation of hepatocellular carcinoma is rarely required for indicating the treatment or even for the utilization of extra scoring in the determination of the patient’s position in the list of liver transplant candidates for those who meet the criteria established by the responsible governmental entity. Furthermore, following the rationale of the increasing number of imaging studies that persists as a worldwide phenomenon, there is also an increase in the frequency of diagnosis of rarer lesions whose imaging findings demonstrate relatively less accumulated evidences and, therefore, pose greater difficulty and challenge in the establishment of a definite diagnosis exclusively by means of imaging findings. In such a context, the article “Uncommon hepatic tumors: iconographic essay – Part 1” published by Pedrassa et al. in the present issue of Radiologia Brasileira presents a providential review of imaging findings of a range of those rarer focal liver lesions, including angiossarcoma, angiolipoma,