1、肝局灶性结节性增生肝局灶性结节性增生Focal nodular hyperplasia(FNH)fnh肝局灶性结节性增生1Outline FNH FNH accounts for approximately 8%of all accounts for approximately 8%of all primary hepatic tumor and is the second primary hepatic tumor and is the second most common benign liver tumor after most common benign liver tumor aft
2、er hemangiomahemangioma.This benign tumour occurs most commonly in women aged 2050 years,but may occur in both men and women at any age,with multiple lesions being found in 20 per cent of cases.FNH FNH fnh肝局灶性结节性增生2 Oral contraceptiveOral contraceptive口服避孕药口服避孕药 use is use is associated with FNH but
3、 the responsibility of associated with FNH but the responsibility of oral contraceptives in the occurrence of the oral contraceptives in the occurrence of the lesion has not been demonstrated.lesion has not been demonstrated.fnh肝局灶性结节性增生3Clinical symptomsClinical symptomsFNH is usually an incidental
4、 finding at imaging and only one-third are discovered because of clinical symptoms such as mild epigastric pain or discomfort and or palpable abdominal mass.Blood liver tests are normal in half of the cases and show only increased in serum gamma-glutamyl-transpeptidase血清r-谷氨酰转肽酶 activity in most of
5、the remnants.fnh肝局灶性结节性增生4 well-circumscribed lobulated mass with central scar(arrow)and radiating septations.P Pathological appearanceathological appearancefnh肝局灶性结节性增生5FNH is defined as a nodule composed of benign-FNH is defined as a nodule composed of benign-appearing hepatocytes occurring in a l
6、iver that is appearing hepatocytes occurring in a liver that is otherwise histologically normal.otherwise histologically normal.FNH is a hyperplastic liver parenchyma FNH is a hyperplastic liver parenchyma（增生性肝实（增生性肝实质）质）subdivided into nodules by fibrous septa that subdivided into nodules by fibrou
7、s septa that may form stellate scarsmay form stellate scars（星状瘢痕）（星状瘢痕）.The lesion is usually solitary(80%)and measures The lesion is usually solitary(80%)and measures less than 5 cm in diameter.Occasionally,FNH is less than 5 cm in diameter.Occasionally,FNH is pedunculatedpedunculated(蒂蒂).fnh肝局灶性结节
8、性增生6Photomicrograph of histopathologic specimen shows regions of nodular hepatocellular proliferation separated by radiating bands and surrounding myxomatous scar(arrows).fnh肝局灶性结节性增生7The margin is sharp,often lobulated and no capsule is present.Hemorrhage and necrosis are rare.At microscopy,the cen
9、tral fibrotic zone is dense connective tissue（致密结缔组织）which contains numerous abnormally thickwalled arteries.Marked proliferation of biliary structures surrounded by inflammatory cells is observed within and at the periphery（边缘）of the fibrous septae.Kupffer cells are also seen within the lesion.fnh肝
10、局灶性结节性增生8FNH FNH classic(80%)non-classic(20%)(a)telangiectatic FNH,(b)with atypia,(c)mixed hyperplastic and adenomatous FNH fnh肝局灶性结节性增生9Diagnosis（CT）Nonenhanced Nonenhanced CT scans CT scans FNH is demonstrated as a focal hypodense FNH is demonstrated as a focal hypodense or isodense mass compared
11、with normal liver.or isodense mass compared with normal liver.A central hypodense scar is depicted in only A central hypodense scar is depicted in only one-third of the cases.Calcifications within one-third of the cases.Calcifications within the central scar are very rare and observed in the central
12、 scar are very rare and observed in only about 1%of the cases .only about 1%of the cases .fnh肝局灶性结节性增生10contrast-enhanced CT scanarterialarterial phase phaseThe lesion enhances rapidly in most cases The lesion enhances rapidly in most cases and the lesion to liver contrast is high and the lesion to
13、liver contrast is high.Lesion contour is well demarcated and may Lesion contour is well demarcated and may be lobulated.At that time,the central scar is be lobulated.At that time,the central scar is hypodense and appears more evident than on hypodense and appears more evident than on unenhanced CT s
14、cans unenhanced CT scans.fnh肝局灶性结节性增生11 portal venous phaseportal venous phaselesion enhancement decreases and the lesion may lesion enhancement decreases and the lesion may be either iso or slightly hyperdense relative to be either iso or slightly hyperdense relative to normal liver.Small-sized FNH
15、 may be barely visible,normal liver.Small-sized FNH may be barely visible,whereas large-sized FNH are visualized due to whereas large-sized FNH are visualized due to deformity in the liver contour or displacement of deformity in the liver contour or displacement of adjacent vessels or depiction of a
16、 relatively adjacent vessels or depiction of a relatively hypoattenuating central scar.hypoattenuating central scar.fnh肝局灶性结节性增生12 delayeddelayed phasephase FNH are isodense relative to normal FNH are isodense relative to normal liver and in most cases,central scars liver and in most cases,central s
17、cars appear iso or hyperattenuating.A central appear iso or hyperattenuating.A central scar is observed more often in large scar is observed more often in large lesions than in small lesions.lesions than in small lesions.fnh肝局灶性结节性增生13CTfnh肝局灶性结节性增生14T1 WI T2WI D Diagnosis（MRI）Nonenhanced Nonenhance
18、d MRIMRI scans scans Typical FNHs are iso or hypointense on T1Typical FNHs are iso or hypointense on T1WIWI and iso or slightly hyperintense on T2and iso or slightly hyperintense on T2WI.WI.The central scar is hypointense on T1The central scar is hypointense on T1WIWI and and strongly hyperintense o
19、n T2strongly hyperintense on T2WI.WI.fnh肝局灶性结节性增生15contrast-enhanced MRI scan dramatic enhancement in the arterial phase,dramatic enhancement in the arterial phase,followed by isointensity of the lesion during the followed by isointensity of the lesion during the portal venous phase.On delayed phase
20、 imaging,portal venous phase.On delayed phase imaging,the central scar shows high signal intensity.the central scar shows high signal intensity.fnh肝局灶性结节性增生16Atypical formsfnh肝局灶性结节性增生17scars are seen in more than 80%of cases.However,radio-pathologic papers have demonstrated that some FNH may have n
21、o scar even at pathology especially FNH measuring less than 3 cm in diameter。fnh肝局灶性结节性增生18 Rarely,scars remain hypodense or isodense on delayed scans or are hypointense on T2-weighted images.These findings may be observed up to 20%of cases.Nearly all FNHs are hypervascular at the arterial phase of
22、the enhancement,but lesion enhancement may vary at the portal phase or on delayed images.Both hypodensity or intensity of the mass on delayed phase,or on both portal vein and delayed phase images as well as hyperdensity-intensity of the mass on the portal vein phase or on both portal vein and delaye
23、d phases may be seen.fnh肝局灶性结节性增生19 Although FNH is a non-encapsulated lesion,capsule like enhancement may be observed on portal vein and on delayed phase scans in about 2536%of the cases.The pseudocapsule(假包膜)is hypointense on T1 and slightly hyperintense on T2.fnh肝局灶性结节性增生20 Differential diagnosis
24、v肝囊肿肝囊肿Hepatic cystv 原发性肝癌原发性肝癌primary hepatic carcinomafnh肝局灶性结节性增生21v肝囊肿肝囊肿Hepatic cystnoncontrast-enhancedcontrast-enhancedCTnonenhancementnonenhancementfnh肝局灶性结节性增生22v肝囊肿肝囊肿Hepatic cystT1WIT2WIMRIcontrast-enhancednonenhancementnonenhancementfnh肝局灶性结节性增生23v 原发性肝癌原发性肝癌primary hepatic carcinoma快进快出快进快出noncontrast-enhancedcontrast-enhancedCTfnh肝局灶性结节性增生24v 原发性肝癌原发性肝癌primary hepaticcarcinoma快进快出快进快出T1WIT2WIcontrast-enhancedfnh肝局灶性结节性增生25Thank you.fnh肝局灶性结节性增生26
