Hepatic Adenoma and Focal Nodular Hyperplasia: Differential Diagnosis and Treatment
PURPOSE To describe the magnetic resonance (MR) imaging features of hepatic adenoma and correlate these findings with histopathologic findings. MATERIALS AND METHODS MR findings of 51 pathologically proved hepatic adenomas in 29 consecutive patients were retrospectively analyzed. T1- and T2-weighted spin-echo (SE) images were obtained in all patients, and contrast material-enhanced MR images were obtained in 16 patients. RESULTS At pathologic analysis, a peripheral rim, observed in 16 (31%) hepatic adenomas, corresponded to pseudocapsule, and tumor heterogeneity, observed in 26 (51%) lesions, corresponded to hemorrhagic necrosis and peliosis. Hyperintensity on T1-weighted SE images was observed in 30 (59%) adenomas; 10 (67%) of 15 hepatic adenomas were hyperintense on contrast-enhanced gradient-echo images, and 13 (45%) of 29 were hyperintense on delayed contrast-enhanced T1-weighted SE images. CONCLUSION Presence of a peripheral rim, heterogeneity, and hyperintensity are common features of hepatic adenoma.