Clinical and imaging features of hepatic focal nodular hyperplasia in 19 cases

Abstract

Objective To explore the clinical and imaging features of focal nodular hyperplasia (FNH) of the liver. Methods From January 2006 to April 2014, 19 patients with FNH of the liver were collected. The serum levels of alpha fetoprotein (AFP), alanine aminotransferase (ALT), aspartate transaminase (AST) and total bilirubin (TBil) were examined. Liver tissues were underwent regular hematoxylin-eosin (HE) staining and pathological analysis. The expression of glypican-3 (Gpc3), CD34 and cytokeratin 19 (CK19) in liver tissues was detected by immunohistochemistry. The results of ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) examination were analyzed. Results Among 19 patients with FNH of the liver (11 males and eight females, the median age was 32 years old), there were two with hepatitis B liver cirrhosis, two with fatty liver disease, one with chronic hepatitis B and the remaining 14 without any chronic liver diseases. Three cases had abdominal pain, one case had diarrhea and one case had abdominal distension, the remaining 14 cases didn't have any symptoms. Nodules were formed by proliferated hepatocytes, there were star shaped scar with radial fiber separator in the central of the lesions with positive CK19 and negative CD34 and Gpc3. The serum AFP level of patients was normal. Both ALT and AST increased in three patients. TBil increased in five patients. Among 10 patients received ultrasound examination, hypoechoic nodules were found in five cases, hyperechoic nodules in two cases, multi hypoechoic to hyperechoic nodules in two cases, and one case was found no nodule, none of them was diagnosed as FNH of the liver. Among 12 received CT examination patients, 10 had low density nodules, two equal density nodules. Nodules of 11 patients had enhancement in arterial phase, five cases showed high density during portal phase or delay phase, three cases showed equal density during portal phase or delay phase, three cases showed low density during portal phase or delay phase, one case had no enhancement in arterial phase and showed equal density during portal phase or delay phase, only two cases were diagnosed as FNH of the liver. Among nine cases who received MRI examination, one case showed equal T1 signal, six cases had low signal, and two cases had high signal; eight cases had long echo T2 signal and one case had equal echo T2 signal; eight cases significantly enhanced during arterial phase, six cases continuously strengthened during portal phase and weakened during equilibrium phase and delay phase, two cases had cyclic strengthen, one case had strip signal without enhancement in arterial phase and strip signal enhanced in the equilibrium phase. One case did not strengthen during enhancement scan in the arterial phase and showed low signal in venous phase, however the central of the lesion showed punctate enhancement. Only one case was diagnosed as FNH of the liver. Nine patients were diagnosed with liver biopsy but without any treatment, seven patients received operation, two patients received radiofrequency treatment during biopsy, and one patient received transcatheter arterial chemoembolization (TACE) treatment. Seven cases were followed up, the follow-up time was one month to three years. New lesion was found in only one case. Conclusion Most FNH of the liver have no clinical symptoms. Combination of CT and MRI may increase the diagnostic rate. Key words: Focal nodular hyperplasia; Neoplasms; Liver; Computed tomography; Magnetic resonance imaging