Imaging features and clinicopathologic study of hepatic focal nodular hyperplasia

Objective: To explore the clinical and imaging charteristics,pathological immunohistochemical features and differential diagnosis of hepatic focal nodular hyperplasia(FNH).Methods: Nine cases of hepatic FNH were analyzed by means of clinicopathologic data analysis,imaging features,histopathology,immunophenotype,cytokeratin 8/18 and cytokeratin 7,α-fetoprotein and Ki-67.In addition,the related literature was reviewed.Results: The imaging demonstrated a solitary nodular,and the plain scan showed isodensity or slightly low density with a low density scar in the centre.Hepatic FNH was a tumor presenting a clear realm and having a mass nodular fibrous scar in the centre.The liver tissue was divided into unequal and irregular nodules by the fibrous scar;thick wall vessels and proliferation of the bile ducts could be seen.Hepatic FNH showed positive immunostaining of cytokeratin 8/18 and cytokeratin 7 in the small bile ducts within the nodule and partial liver cells surrounding.CD34 was positively expressed on blood sinus endothelial cells of the nodules and fiber interval.Both the hyperplasia bile ducts and the liver cells were negative for α-fetoprotein and lowly expressed for Ki-67.Conclusions: FNH is widely recognized as a hyperplasia reaction of live cells to vascular malformations;therefore,hepatic FNH is a kind of benign tumor-like lesion.Asymptomatic persons with clear diagnosis should be followed-up regularly and reviewed after operation excision.