Partial nodular transformation in a cirrhotic liver

We present a case of partial nodular transformation (PNT) of the liver in a 57-year-old man with a history of heavy drinking. On computed tomography, a low-density mass, measuring 3 cm in diameter, and associated with portal flow defect was visualized. Based on this finding and on the findings of other imaging studies, hepatic resection was performed because of suspected hepatocellular carcinoma. Pathology examination of the excised specimen showed small portal tracts in the lesion. The findings for the rest of the liver were suggestive of mild liver cirrhosis. While PNT is similar to nodular regenerative hyperplasia (NRH), in NRH there is diffuse nodular transformation of the whole liver, whereas in PNT only the area adjacent to the porta hepatis is affected. The portal flow defect in PNT may be the result of attenuation of the portal tracts in the lesion. This case is of interest because there was only one PNT lesion, rather than multiple lesions, and because it occurred in a cirrhotic liver, thus giving rise to the suspicion of hepatocellular carcinoma. PNT is a benign disorder, thus it is essential to establish a definitive diagnosis by imaging and ultrasound-guided histological biopsy to prevent unnecessary hepatic resection.     

Focal nodular hyperplasia of the liver: direct evidence of circulatory disturbances

Focal nodular hyperplasia of the liver is a lesion characterized by a well-circumscribed region of hyperplastic liver parenchyma and contains a stellate fibrous scar. The lesion is thought to be because of liver-cell hyperplasia that is caused by focal circulatory disturbances. We describe here a pediatric case of this lesion that provided direct histopathologic evidence of circulatory disturbances. We identified arterial and portal thrombi, as well as recanalization of arteries in the nodule. Hepatic necrosis was also seen in the lesion. We speculate that thrombosis of the hepatic artery and/or portal vein was the cause of hepatic necrosis and that reperfusion following hepatic arterial recanalization resulted in nodule formation. Although there was no stellate scar present in our case, the presence of bile ductular proliferation at the periphery of the nodule was helpful in distinguishing this lesion from adenoma and hepatocellular carcinoma. The early stage of nodular formation may explain the lack of a stellate scar in our case. The patient was treated earlier with actinomycin D and vincristine following surgical excision of Wilms' tumor. It is possible that such chemotherapy contributed to thrombosis in our case.     

Benign nodular hepatocellular lesions caused by abnormal hepatic circulation: etiological analysis and introduction of a new concept

Abstract Problems in definitive diagnosis and etiology of various benign nodular hepatocellular lesions were evaluated. Of these lesions, focal nodular hyperplasia (FNH), nodular regenerative hyperplasia (NRH), nodular lesions associated with idiopathic portal hypertension (IPH), non‐cirrhotic large regenerative nodules (LRN), hepatocellular adenoma (HA)‐like hyperplastic nodules, and partial nodular transformation (PNT) have been suggested to be related to abnormal hepatic circulation. However, the following points are considered to need further clarification: (i) is the abnormal circulation caused by thrombosis, vasculitis, or congenital anomaly?; (ii) is thrombosis a cause or a result of congestion?; (iii) are impaired blood vessels primarily the portal veins or arteries?; (iv) how are these disorders related to various syndromes, immunological abnormalities and abnormal blood flow of other organs, which are reported to coexist with these lesions often?; and (v) how should non‐typical cases, which differ from typical cases, be interpreted? In addition, a concept that may lead to solving these problems (anomalous portal tract syndrome; a hypothesis that congenital vascular anomaly is the origin of these benign nodular hepatocellular lesions) was introduced.     

Huge focal nodular hyperplasia difficult to distinguish from well-differentiated hepatocellular carcinoma

We present a 43‐year‐old man with huge focal nodular hyperplasia (FNH) that was difficult to distinguish from well‐differentiated hepatocellular carcinoma (HCC). He previously had abnormal portal vein circulation due to hypoplasia of the intrahepatic portal vein, which was treated with a superior mesenteric vein–inferior vena cava shunt. Laboratory findings included predominantly indirect hyperbilirubinemia with concomitant elevation in aspartate aminotransferase (AST), alanine aminotransferase (ALT), and ammonia. Serum α‐fetoprotein and des‐γ‐carboxy prothrombin were slightly elevated. Multidetector‐row computed tomography detected the primary tumor in the left liver lobe, which partially showed a central stellate scar. Gd ethoxybenzyl diethylenetriamine pentaacetic acid‐enhanced magnetic resonance imaging showed some low‐intensity areas in the tumor in the hepatocyte phase. 99mTc‐galactosyl human serum albumin scintigraphy showed normal intake of agent in the tumor. We could not rule out well‐differentiated HCC. Extended left hepatectomy was performed. Final histopathological findings showed that most of the tumor was FNH against a background of portal vein hypoplasia with moderate atypia and hemorrhage. And immunohistochemical analysis revealed high expression of organic anion transporter (OATP) 1B3 and low expression of multidrug resistance‐associated protein (MRP) 2 in a part of the tumor. The patient has remained alive with no hepatic lesion for 1 year after surgery. We describe a case of huge FNH that was difficult to distinguish from well‐differentiated HCC even by current fully preoperative imaging technology and demonstrate the effectiveness of curative surgical resection.     

Solitary necrotic nodule of the liver

Solitary necrotic nodule of the liver is a rare benign lesion; only 22 cases have been reported to date. An unsolved problem in treating these lesions involves the difficulties in differential diagnosis; specific features of necrotic nodule of the liver in preoperative examinations have not been identified. Here, we report a patient with resected solitary necrotic nodule of the liver with preoperative features shown on ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) examinations. A 48‐year‐old woman was referred to our hospital on December 13, 1999 because a hypoechoic lesion in Couinaud's segment VIII of the liver had been incidentally detected on US. A CT scan confirmed the presence of a round hypodense lesion, measuring 2 cm in diameter. No significant enhancement was recognized on dynamic MRI study. T1‐Weighted MRI examinations demonstrated a low intensity showing a triple‐layered pattern with low‐iso‐low intensity in the lesion, while T2‐weighted images demonstrated a slightly high intensity in the lesion. These features suggested fibrous tissue. Histological examinations following partial resection of the liver revealed a solitary necrotic nodule of the liver. Combination studies, including MRI examinations, would be useful for the preoperative diagnosis of a solitary necrotic nodule of the liver.     

肝局灶性结节增生的MRI诊断及鉴别诊断价值

目的探讨肝脏局灶性结节增生的MRI诊断及鉴别诊断价值。方法回顾性分析16例肝脏局灶性结节增生的MRI平扫及动态增强表现。结果平扫15例T1W1呈稍低信号,1例呈低信号;T2WI16例均呈稍高信号,14例可见中心斑痕;动态增强16例动脉期均明显均匀强化,静脉期及延迟期呈等及稍高信号,中心斑痕延迟强化。结论MRI平扫及动态增强对其诊断具有一定临床意义。     

Focal nodular hyperplasia-like nodule with reduced expression of organic anion transporter 1B3 in alcoholic liver cirrhosis

We report a patient with alcoholic liver cirrhosis who had a 15 mm focal nodular hyperplasia (FNH)-like nodule in the liver. This FNH-like nodule was diagnosed as hepatocellular carcinoma (HCC) mainly based on hypervascularity during the hepatic arterial phase, washout pattern during the equilibrium phase and low signal intensity during the hepatobiliary phase in gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI; it was surgically resected. Its histology exhibited hepatocyte hyperplasia, fibrous septa containing unpaired small arteries accompanied by reactive bile ductules, remarkable iron deposits and sinusoidal capillarization, and was compatible with the diagnosis of an FNH-like nodule. When we analyzed the images of the present nodule retrospectively, low signal intensity on in-phase and isosignal intensity on opposed-phase T1-weighted MRI may have reflected iron deposits in the FNH-like nodule. In addition, a low signal intensity on T2-weighted MRI and no detection in diffusion-weighted MRI may help in distinguishing FNH-like nodules from HCC, since these image findings are inconsistent with typical HCC. Immunohistochemical analysis revealed a markedly reduced expression of organic anion transporter (OATP) 1B3 in this nodule, which implied decreased Gd-EOB-DTPA uptake by hepatocytes and accounted for the low signal intensity during the hepatobiliary phase on Gd-EOB-DTPA-enhanced MRI. To the best of our knowledge this is the first report in which an FNH-like nodule was assessed for OATP1B3 expression.     

特发性门静脉高压的肝脏病理学分析

耳的观察特发性门静脉高压的肝脏病理改变,明确病理诊断标准,并探讨临床病理联系。方法收集中日友好医院2005年1月-2007年3月病理确诊的特发性门静脉高压病例29例,对其肝组织行HE、网织纤维加Masson三色染色,以及α-平滑肌肌动蛋白、细胞角蛋白7、细胞角蛋白19免疫组织化学染色,并分析病变特点。结果29例中男9例,女20例。临床有门静脉高压、脾大等症状、体征。23例临床误诊为肝硬化。主要病理改变有：明显的汇管区纤维化,伴终末门静脉细小分支闭锁（缺乏）及不完全细纤维隔形成。部分门静脉支扩张并疝入小叶内。肝细胞萎缩及结节状再生相伴。结论特发性门静脉高压的肝脏病变具有一定的形态学特征,汇管区纤维化、门静脉小支闭锁,部分门静脉分支疝入肝实质,肝细胞萎缩及结节状再生相伴,较具诊断价值。     

增强MRI扫描在乙型肝炎肝硬化背景下对原发性肝癌的诊断价值分析*

目的 研究采用钆塞酸二钠(Gd-EOB-DTPA)增强磁共振成像(MRI)对乙型肝炎肝硬化背景下原发性肝癌(PLC)的诊断价值。方法 2018年12月～2020年12月我院收治的乙型肝炎肝硬化背景下肝脏局灶性病变患者147例,均行Gd-EOB-DTPA肝脏增强MRI扫描,观察病灶强化特点和各序列信号强度,包括T1加权像(T₁WI)、T2加权像(T₂WI)及动脉期、门脉期、肝胆特异期和磁共振弥散加权成像(DWI)病灶的信号强度。采用受试者工作特征(ROC)曲线下面积(AUC)分析上述信号特征对PLC的诊断效能。结果 在147例患者中,发现PLC者102例,病灶大小为0.9～2.9 cm,平均为(1.8±0.6)cm,肝脏异型性增生结节45例,病灶大小为0.8～2.5 cm,平均为(1.4±0.2)cm;增强MRI扫描显示,84例表现为动脉期病灶呈低或等强化,门静脉期或延迟期呈低强化,63例表现为动脉期明显强化,门静脉期或延迟期未廓清;PLC组病灶T₁WI低信号、T₂WI高信号、DWI高信号、动脉期高强化和肝胆期低信号表现占比分别为50.0%、79.4%、82.4%、52.9%和94.1%,显著高于非PLC组(20.0%、20.0%、26.7%、20.0%和20.0%,P＜0.05);ROC分析结果显示病灶T₁WI低信号(AUC=0.670,敏感度=0.451)、T₂WI高信号(AUC=0.817,敏感度=0.745)、DWI高信号(AUC=0.754,敏感度=0.863)、动脉期高强化(AUC=0.693,敏感度=0.520)和肝胆期低信号(AUC=0.891,敏感度=0.892)对PLC具有一定的诊断效能(P＜0.05)。结论 增强MRI扫描在乙型肝炎肝硬化背景下早期发现PLC具有重要的诊断价值,临床应不断总结其特点变化,提高早期诊断率。     

Focal nodular hyperplasia‐like lesion of the liver with focal adenoma features associated with idiopathic portal hypertension

Great progress has been made in the diagnosis of focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) in the last few years due to the use of molecular criteria. This has allowed us to identify a new type of hepatic nodule. In this case report, we present a male patient with a hepatic nodule associated with idiopathic portal hypertension (IPH) pathologically exhibiting not only the morphological features of FNH, such as ductular reactions, dilated sinusoids, major vascular abnormalities and an immunohistochemical “map‐like” pattern of glutamine synthetase (GS), but also the immunohistological features of focal HCA, such as strong expression of serum amyloid A and C‐reactive protein and weak expression of GS. As the final diagnosis, the nodule was identified as an FNH‐like lesion with focal inflammatory hepatocellular adenoma.     

Clinical evaluation of magnetic resonance imaging flowmetry of portal and hepatic veins in patients following hepatectomy.

BACKGROUND: Hepatic blood flow was associated with degree of hepatic damage. Measurements of blood flow using ultrasonography (US) may vary due to any observer's and patient's conditions. The utility of magnetic resonance imaging (MRI) flowmetry in portal and hepatic veins was assessed. PATIENTS AND METHODS: Using the phase-contrast method, the mean flow velocity of portal (PVF) and hepatic vein (HVF) were determined by MRI and US in 75 consecutive patients with liver diseases, including 58 patients undergoing hepatectomy. The correlations between these parameters and clinicopathological findings were examined. RESULTS: PVF and HVF measured by MRI flowmetry were 12.8+/-4.5 and 14.7+/-5.3 cm/s, respectively. There was no significant correlation of both flows between MRI and US. PVF correlated significantly with portal pressure (r = -0.722; P < 0.05). There was a negative correlation between HVF and histological activity index score (r = -0.366; P < 0.05). PVF and HVF were lower in patients with cirrhosis and higher staging score (2-4) and PVF was lower in patients with higher grading score (2-3; P < 0.05). PVF and HVF were not significantly associated with postoperative complications. CONCLUSIONS: Our results suggest that MRI flowmetry is a potentially useful tool for measurement of hepatic blood flow and recommend its use for estimation of liver cirrhosis-associated impairment.     

Congenital absence of the portal vein.

Absence of the terminal portion of the portal vein and its intrahepatic branches was demonstrated in a 22-year-old woman with focal nodular hyperplasia (FNH) of the liver. Various imaging studies and angiography showed that the portal vein entered into the inferior vena cava just above the renal veins. The clinical and radiological features of this patient and nine previously reported cases of this entity are herein reviewed.     

Preoperative portal vein embolisation for primary and metastatic liver tumours: volume effects, efficacy, complications and short-term outcome

BackgroundThe aim of portal vein embolisation is to induce hyperplasia of normal tissue when resection of a cancerous portion of the liver is contraindicated only by the volume of liver that would remain following operation.MethodsEight patients with inoperable liver tumours (3 women and 5 men, median age 69.5 years, 3 colorectal hepatic metastasts,2 choloangiocarcinomas and 3 hepatocellular cancers) were selected for portal vein embolisation. Selected portal branches were occluded with microparticles and coils. Liver volumes were determined by magnetic resonance imaging (MRI) before embolisation and again before operation.ResultsEmbolisation was successfully performed in all 8 patients, 7 by the percutaneous-transhepatic route, while one patient required open cannulation of a mesenteric vein. Management was altered in 6 patients who proceded to ‘curative’ resection; projected remaining liver volumes increased (Wilcoxon''s matched pairs test p=0.02) from a median of 361 cc to a median of 550 cc; two patients had disease progression such that operation was no longer indicated. In one patient a misplaced coil unintentionally occluded a portal branch to normal liver.ConclusionsPortal vein embolisation produced appreciable hyperplasia of the normal liver and extended the option of ‘curative’ operation to 6 out of the 8 cases attempted. Complications can occur. The long-term results following operation are unknown.     

原发性肝癌与肝局灶性结节性增生MRI平扫及强化特征研究

目的 分析原发性肝癌（PLC）和肝局灶性结节性增生（FNH）磁共振成像（MRI）平扫及强化特征的差异,以探讨应用MRI鉴别诊断两者的方法。方法 2014年7月~2016年6月我院诊治的26例FNH和36例PLC患者,使用SuperMark 1.5 T磁共振成像仪行MRI平扫和动态增强扫描。比较两组病灶分布情况和影像学表现特征。结果 FNH病灶在左叶和右叶的比例分别为30.8%和69.2%,与PLC病灶（38.9%和61.1%）比,差异无统计学意义（均P>0.05）,但FNH病灶位于肝包膜下的比例为46.2%,显著高于PLC组的16.7%（P<0.05）;FNH病灶直径为（4.8±0.8） cm,与PLC病灶的（5.1±0.8） cm比,差异无统计学意义（P>0.05）;平扫结果显示FNH病灶T1低信号和等信号比例分别为84.6%和15.4%,与PLC病灶（88.9%和11.1%）比,差异无统计学意义（P>0.05）;FNH病灶T2高信号和等信号比例分别为88.5%和11.5%,与PLC病灶（91.7%和8.3%）比,差异无统计学意义（P>0.05）;PLC病灶内往往显示长T1和长T2两个信号的坏死区,还出现短T1和混杂T2的出血信号,而部分FNH病灶中心处可见星芒状的结构,呈现出长T1和长T2信号。FNH显示中心瘢痕和供血动脉的比例分别为65.4%和46.2%,均显著高于PLC病灶（8.3%和8.3%,P<0.05）,存在门静脉栓子和肝硬化的比例分别为0.0%和7.7%,均显著低于PLC病灶（分别为25.0%和55.6%,P<0.05）,快进快出强化和淋巴结肿大的比例分别为88.5%和0.0%,与PLC病灶的86.1%和11.1%比,差异均无统计学意义（P>0.05）。结论 使用MRI检查可清晰地区分PLC与FNH的影像学特征,有助于两者的判别和鉴别诊断。     

超声检查门静脉海绵样变特征表现

目的 探讨门静脉海绵样变(CTPV)及其相关并发症的超声表现特征,并分析了超声漏诊的原因。方法 2017年6月～2020年6月首都医科大学附属北京地坛医院诊治的101例CTPV患者,经CT和MRI增强扫描诊断,接受腹部超声检查。总结CTPV及其相关并发症超声图像表现特征,并分析超声漏诊的原因,提出解决策略。结果 在本组101例CTPV患者中,超声诊断82例(82.2%),漏诊19例(17.8%);在超声诊断病例中,82例(100.0%)患者门静脉主干及其分支周围出现广泛或局部蜂窝状粗细不等的血管结构,70例(85.4%)出现门静脉管壁增厚,76例(92.7%)在迂曲扩张的蜂窝状血管结构内部呈红蓝相间的丰富的血流信号,脉冲多普勒测得门静脉样低速血流频谱,10例(12.2%)门脉周围迂曲扩张蜂窝状血管压迫胆管,导致胆管扩张,8例(9.6%)出现胆囊增大,6例(7.4%)出现胆囊结石,5例(6.1%)出现胆管结石,5例(6.1%)出现门体分流。结论 超声是诊断CTPV的首选影像学方法,超声漏诊的原因主要为海绵样变血管腔细、病变范围小,腹部胀气,假性胆管肿瘤征,肋间隙或胸骨下角窄。利用腹腔积液和胆囊等声窗扫查肝脏,采用超声造影技术或结合其他影像学技术检查可减少漏诊。     

Insight into congenital absence of the portal vein： Is it rare？

Congenital absence of portal vein （CAPV） was a rare event in the past. However, the number of detected CAPV cases has increased in recent years because of advances in imaging techniques. Patients with CAPV present with portal hypertension （PH） or portosystemic encephalopathy （PSE）, but these conditions rarely occur until the patients grow up or become old. The patients usually visit doctors for the complications of venous shunts, hepatic or cardiac abnormalities detected by ultrasonography （US）, computed tomography （CT） and magnetic resonance imaging （MR1）. The etiology of this disease is not clear, but most investigators consider that it is associated with abnormal embryologic development of the portal vein. Usually, surgical intervention can relieve the symptoms and prevent occurrence of complications in CAPV patients. Moreover, its management should be stressed on a case-by-case basis, depending on the type or anatomy of the disease, as well as the symptoms and clinical conditions of the patient.     

原发性肝癌门静脉侵犯MRI表现

目的手术前准确评价原发性肝癌(HCC)的门静脉瘤栓.方法 HCC 25例,门静脉瘤栓均经其它检查方法证实.磁共振为1.0T 超导系统.轴位扫描序列为 SE 序列 T1权重和 T2权重及 FLASH 序列.冠状扫描序列为 FLASH.结果门静脉瘤栓的信号强度和肿瘤一致.腔内门静脉瘤栓16例;6例为门静脉闭塞;3例为门静脉弥漫性狭窄.门静脉瘤栓MRI 表现为异常信号取代正常的门静脉流空,门静脉截断、门静脉不规则狭窄及侧支血管网形成.结论结合自旋回波和梯度回波扫描,MRI 评价门静脉瘤栓敏感性高,特征性强,而且无创伤性.     

Diagnosis and treatment of focal nodular hyperplasia

Focal nodular hyperplasia is an uncommon, benign lesion of the liver of minimal clinical significance. Its importance lies in differentiating it from clinically significant lesions such as liver cell adenoma and hepatocellular carcinoma. The purpose of this review is to provide a background on the pathogenesis of focal nodular hyperplasia, discuss current imaging modalities which provide the most specificity in diagnosis, and provide an update on the accepted management of these lesions. While debate still exists, most current authors believe that focal nodular hyperplasia represents a local response of the liver to injury. The source of that injury seems to be vascular malformations. Magnetic resonance imaging (MRI) provides the most specificity in diagnosis, although the characteristics are still being described. Classically, the lesions will be isointense on T2-weighted images with rapid homogenous contrast enhancement and delayed enhancing central stellate scar. Surgical resection is limited to symptomatic lesions or lesions with atypical imaging characteristics suggesting the possibility of a malignant diagnosis. Percutaneous biopsy can be helpful in those lesions where there is an overall high suspicion of focal nodular hyperplasia, but some of the clinical aspects or imaging characteristics are atypical for the diagnosis. The use of embolization as first line therapy for symptomatic lesions deserves further investigation.     

Magnetic resonance imaging of portal vein invasion in hepatocellular carcinoma: Results from 25 cases

AIM: To pre-operatively assess tumor thromboses associated with hepatocellular carcinoma in the portal vein. METHODS: Twenty-five patients diagnosed with a thrombus due to hepatocellular carcinoma were included in the study. MR imaging was performed with a 1.0T superconducting magnetic imaging system. Both T1 and T2 weighed images as well as FLASH sequences were obtained in the transverse plane, and additional FLASH images were obtained in the coronal plane. RESULTS: Thromboses located in the portal vein had signal intensities similar to those of the main tumor. An intrinsic portal vein thrombus was found in 16 patients, and six thromboses were occlusive. Thromboses were found in the diffuse narrow portal branches of 3 patients. The portal venous thromboses displayed an area of signal intensity that replaced the normal flow void of the portal vein. The affected portal veins displayed a stumpy appearance, had irregular areas of stenosis, and showed formation of a vascular net. CONCLUSION: MRI was more sensitive, specific, and noninvasive for detecting a portal tumor thrombus, and can be used jointly with spin echo (SE) and gradient echo (GRE) imaging techniques.     

Pathology of portal hypertension

Abstract   Portal hypertension may be the result of intra- and extrahepatic impediment of portal venous blood flow. Portal vein thrombosis is the major cause of prehepatic portal hypertension, and hepatic vein occlusion, congestive heart failure and constrictive pericarditis lead to posthepatic portal hypertension. Cirrhosis is the most common intrahepatic lesion responsible for portal hypertension. Idiopathic non-cirrhotic portal hypertension results from obliterative injuries more specifically directed to intrahepatic portal vascular structures (macro- and microvascular portal vein disease). Under these conditions, portal vascular dilatation, herniation into the periportal parenchyma and paraportal shunt vessels resemble collateral pathways. The liver parenchyma often shows nodular transformation which may even be the only clue to the presence of small portal vein obstruction in a small liver biopsy. Thus, the morphologic changes associated with idiopathic portal hypertension may be subtle and non-specific. Their recognition, particularly in the liver biopsy, is a challenge to the pathologist.