肝脏局灶性结节增生13例磁共振误诊分析及病理对照OACSTPCD

Objective To explore the possible causes of misdiagnosis of hepatic focal nodular hyperplasia(FNH)by magnetic resonance imaging(MRI)in comparison with pathological findings.Methods A retrospective analysis was performed on the data from hepatic FNH patients confirmed by pathology(21 cases)at the Lishui Central Hospital in Zhejiang Province from Jan.2015 to Jan.2023.Two evaluators assessed the MRI features of the lesions(including general characteristics,signals on the plain scan,enhancement patterns,and accompanying features of the surrounding tissues)without the knowledge of the pathological results,and made the diagnosis based on consensus.Misdiagnosed cases were subjected to pathological findings and analysis of the reasons for misdiagnosis using the pathological results as the gold standard.Results Thirteen patients(with an average of one FNH lesion per person)were misdiagnosed,with four cases misdiagnosed as hepatocellular carcinoma,one case as a mass-forming intrahepatic cholangiocarcinoma,one case as a metastatic tumor,three cases as solitary fibrous tumors,two cases as epithelioid angiomyolipomas,and two cases as hepatocellular adenomas.In two cases with"false capsule signs"on MRI,no obvious false capsule was found under the microscope,while three lesions with false capsules under the microscope were not identified as having the"false capsule sign"on MRI.Three lesions showed"local necrosis"on MRI,but none of the 13 lesions showed signs of local ischemic necrosis under the microscope.Two lesions were evaluated as having"fatty degeneration signs"on MRI,and both showed obvious accumulation of fat cells under the microscope.Lesions without"fatty degeneration signs"on MRI also showed no obvious fatty degeneration under the microscope.Eleven lesions showed scars under the microscope,but none of the 13 lesions were identified as having"delayed enhanced scars"on MRI.Conclusion The main reasons for misdiagnosis of hepatic FNH by MRI are the absence of central scars or atypical morphology/signal/enhancement of scars,the appearance of"fatty degeneration sign"of hepatocellular carcinoma in the lesions,and misjudgment of the presence of the"false capsule sign"of hepatocellular carcinoma.In addition,misdiagnosis may also be caused by the exogenous growth of lesions that are closely adhered to other organs outside the liver and by evaluators being influenced by clinical history.