Imaging features of nodular regenerative hyperplasia of the liver mimicking hepatic metastases

We described the sonographic, computed tomographic (CT), and magnetic resonance (MR) imaging features of one atypical case of nodular regenerative hyperplasia of the liver. The presence of multiple hepatic nodules suggested the diagnosis of metastatic disease to the liver because of a peripheral rim of enhancement on CT obtained after intravenous administration of contrast material and a halo sign on T2-weighted spin-echo MR imaging. Examination of the pathologic specimen obtained after surgical biopsy showed that the nodules were made of hepatocytes, with a nodular arrangement surrounded by peliosis, without fibrosis or cirrhosis, These findings suggested that peliosis may cause peripheral rim of enhancement on CT and halo sign on MR imaging. In light of this case, nodular regenerative hyperplasia of the liver should be considered in the differential diagnosis of hepatic metastases.