Focal hyperplastic hepatocellular nodules in hepatic venous outflow obstruction: a clinicopathological study of four patients and 24 nodules

Focal nodular hyperplasia-like nodules arising in the setting of hepatic vascular disorders with portosystemic shunting show β-catenin activation

Hepatocellular nodules can develop in the setting of chronic hepatic vascular disorders including those characterized by portosystemic shunts such as Abernethy malformation and post-Fontan procedure. The nodules can range from benign lesions such as regenerative nodules, focal nodular hyperplasia (FNH), and hepatocellular adenoma (HCA) to malignant neoplasms such as hepatocellular carcinoma (HCC). In many instances, these nodules are difficult to place into well-defined categories based on radiologic or histologic features. Nodular lesions that resemble FNH are common in this context and have been described as FNH-like nodules, the nature of which is not well-established. This study examines 6 liver resections from patients with vascular disease characterized by portosystemic shunts. A wide range of nodules were present in these cases, including regenerative nodules (n = 2), FNH and FNH-like (n = 30), HCA (n = 10), HCA-like (n = 13), and HCC (n = 2). Six nodules from 3 patients were categorized as FNH-like due to one or more features such as nodular architecture, fibrous septa, and ductular reaction, but lack of typical map-like glutamine synthetase (GS) staining. Further characterization of these 6 FNH-like nodules showed diffuse GS staining in all nodules (3 diffuse homogeneous, 3 diffuse heterogeneous). Targeted next-generation sequencing identified CTNNB1 alterations in all tested FNH-like nodules (n = 4). These results indicate that FNH-like nodules in the setting of chronic hepatic vascular disorders can be neoplastic. Since the presence of β-catenin activation portends a potential risk for malignant progression, GS and β-catenin immunohistochemistry should be obtained in all cases showing FNH-like morphology, with molecular analysis performed in cases with indeterminate staining pattern.

Focal Liver Lesions in Budd-Chiari Syndrome: Spectrum of Imaging Findings

Budd-Chiari syndrome (BCS) is a rare clinical entity characterized by hepatic venous outflow obstruction, resulting in liver congestion and subsequent chronic parenchymal damage. This condition often leads to the development of focal liver lesions, including benign focal nodular hyperplasia-like regenerative nodules, hepatocellular carcinoma, and perfusion-related pseudo-lesions. Computed tomography, ultrasound, and magnetic resonance are the commonly employed imaging modalities for the follow-up of BCS patients and for the detection and characterization of new-onset lesions. The accurate differentiation between benign and malignant nodules is crucial for optimal patient management and treatment planning. However, it can be challenging due to the variable and overlapping characteristics observed. This review aims to provide a comprehensive overview of the imaging features and differential diagnosis of focal liver lesions in BCS, emphasizing the key findings and discussing the challenges associated with their interpretation, with the purpose of facilitating the subsequent clinical decision-making.

Budd-Chiari syndrome in myeloproliferative neoplasms: A review of literature

Myeloproliferative neoplasms (MPNs) are defined as clonal disorders of the hematopoietic stem cell in which an exaggerated production of terminally differentiated myeloid cells occurs. Classical, Philadelphia-negative MPNs, i.e., polycythemia vera, essential thrombocythemia and primary myelofibrosis, exhibit a propensity towards the development of thrombotic complications that can occur in unusual sites, e.g., portal, splanchnic or hepatic veins, the placenta or cerebral sinuses. The pathogenesis of thrombotic events in MPNs is complex and requires an intricate mechanism involving endothelial injury, stasis, elevated leukocyte adhesion, integrins, neutrophil extracellular traps, somatic mutations (e.g., the V617F point mutation in the JAK2 gene), microparticles, circulating endothelial cells, and other factors, to name a few. Herein, we review the available data on Budd-Chiari syndrome in Philadelphia-negative MPNs, with a particular focus on its epidemiology, pathogenesis, histopathology, risk factors, classification, clinical presentation, diagnosis, and management.

Budd-Chiari syndrome: consensus guidance of the Asian Pacific Association for the study of the liver (APASL)

Budd Chiari syndrome (BCS) is a diverse disease with regard to the site of obstruction, the predisposing thrombophilic disorders and clinical presentation across the Asia-Pacific region. The hepatic vein ostial stenosis and short segment thrombosis are common in some parts of Asia-Pacific region, while membranous obstruction of the vena cava is common in some and complete thrombosis of hepatic veins in others. Prevalence of myeloproliferative neoplasms and other thrombophilic disorders in BCS varies from region to region and with different sites of obstruction. This heterogeneity also raises several issues and dilemmas in evaluation and approach to management of a patient with BCS. The opportunity to recanalize hepatic vein in patients with hepatic vein ostial stenosis or inferior vena cava stenting or pasty among those membranous obstruction of the vena cava is a unique opportunity in the Asia-Pacific region to restore hepatic outflow closely mimicking physiology. In order to address these issues arising out of the diversity as well as the unique features in the region, the Asia Pacific Association for Study of Liver has formulated these guidelines for clinicians.

Hepatocellular adenomas: recent updates

Hepatocellular adenoma (HCA) is a heterogeneous entity, from both the histomorphological and molecular aspects, and the resultant subclassification has brought a strong translational impact for both pathologists and clinicians. In this review, we provide an overview of the recent updates on HCA from the pathologists’ perspective and discuss several practical issues and pitfalls that may be useful for diagnostic practice.

Diagnosis of Focal Nodular Hyperplasia (FNH) after Liver Transplantation

Following liver transplantation (LT), recipients can develop benign and malignant hepatic masses just like any other patient. Patients transplanted for hepatocellular carcinoma (HCC) undergo surveillance imaging, and any new mass seen on imaging must be carefully evaluated to rule out recurrent cancer. Focal nodular hyperplasia (FNH) is a benign tumor of the liver that most often occurs in women and is rarely symptomatic. It is important to distinguish FNH from more serious etiologies, such as recurrent HCC and other malignancies, since the treatments differ greatly. To date, there have been very few reports of FNH occurring in a liver allograft. We present a case of a patient with a history of a carcinoid tumor who underwent LT for HCC. Several years posttransplant, the patient was found to have a liver mass with classic features of HCC on imaging. The liver biopsy revealed the unexpected diagnosis of FNH. This finding avoided unnecessary treatment for HCC, which is associated with morbidity, especially in the posttransplant setting. We present our diagnostic approach, discuss the clinicopathologic and imaging findings of FNH, and review the literature on FNH in the posttransplant setting.

Is There Still a Role for Surgical Shunts in the Treatment of Budd-Chiari Syndrome? A 25-Year Experience

PURPOSE

To investigate the long-term results of shunt surgery in the treatment of Budd-Chiari Syndrome.

METHODS

Medical records of patients treated with Budd-Chiari Syndrome between 1993 and 2006 were reviewed.

RESULTS

Thirty-seven patients (26 female, 11 male) were identified, with a median age of 30 years (range 14-51). Median duration of symptoms was 3 months (range 1 month to 10 years). Twenty-five patients, all in acute or subacute stages of disease, were treated surgically. Constructed shunts were mesoatrial in 17, portocaval in five (one was converted from a failed portorenal shunt) and mesocaval in three. Median portal pressure decreased from 44 cm H₂O (range 31-55) to 20 cm H₂O (range 5-27). Seven patients (28%) died in the perioperative period. Eighteen patients (72%) were followed up for a median of 186 months (24-241 months). Seven patients died during follow-up, five due to reasons related to the underlying cause and treatment. Remaining 11 patients (61%) were alive at a median of 18 years (13-25 years) with patent shunts. One-, 5-, and 10-year survival rates in patients undergoing shunt surgery were 78%, 72%, and 66%, respectively.

CONCLUSION

Portosystemic shunts may still be considered when expertise for transjugular intrahepatic portosystemic shunt or liver transplantation is not available.

Development of Hepatocellular Carcinoma in Patients with Glycogen Storage Disease: a Single Center Retrospective Study

BACKGROUND

Glycogen storage disease (GSD) is an inherited disorder leading to abnormal glucose metabolism and glycogen accumulation, and is associated with various complications including hepatic adenoma and hepatocellular carcinoma. The aim of this study was to analyze the risk factors for hepatic adenoma and its malignant change, and the hepatocellular carcinoma-free survival rate in patients with GSD who developed adenoma.

METHODS

A total of 72 patients with GSD who were enrolled from March 1982 to September 2013 at Seoul National University Children's Hospital were retrospectively analyzed, and the median follow-up period was 19.2 years.

RESULTS

Thirty-two patients (44.4%) developed hepatic adenoma at an age range of 7.9-26.3 years (median, 14.3 years). Among the 32 patients with hepatic adenoma, 4 patients (12.5%) developed hepatocellular carcinoma on an average interval of 6.7 years between the diagnosis of adenoma and the development of hepatocellular carcinoma. GSD type I and portacaval shunt operation were found to be the risk factors for hepatic adenoma development. The hepatocellular carcinoma-free survival rate at 10 years from adenoma development was 82%.

CONCLUSION

The present study found that portacaval shunt operation increases the risk of development of hepatic adenoma in GSD patients, especially in GSD type I. The hepatic adenoma in GSD patients has a potential of malignant transformation, which should be keep in mind in follow-up process of the disease.

Hepatic pathology in patients after Fontan operation: A computed tomography imaging study

BACKGROUND

Hepatic dysfunction is an important long-term complication in Fontan patients. The purpose of this study was to evaluate the hepatic computed tomography (CT) findings after Fontan surgery and identify their association with clinical parameters.

METHODS

This study recruited 43 patients (23 male and 20 female patients aged 15.3 ± 6.8 years), who underwent Fontan surgery. Medical records were reviewed to collect their age, sex, congenital heart disease type, date of Fontan surgery, laboratory data, and hepatic CT findings. The relationship between hepatic findings and clinical parameters was analyzed.

RESULTS

The follow-up duration was 6.8 ± 4.1 years. Abnormal hepatic parenchymal enhancement was observed in 77% of the patients, with mild degree in 18, moderate degree in 10, and severe degree in 5 patients. According to the univariate analysis, risk factors for hepatic parenchymal enhancement were follow-up duration (odds ratio [OR]: 1.354 [95% confidence interval (CI): 1.024-2.078]; p = 0.042), hypoplastic left heart syndrome (HLHS) (OR: 3.262 [95% CI: 1.145-5.628]; p = 0.002), mean pulmonary artery pressure (OR: 1.598 [95% CI: 1.089-2.132]; p = 0.026), pulmonary vascular resistance index (OR: 1.263 [95% CI: 1.068-1.245]; p = 0.032), and brain natriuretic peptide (OR: 1.956 [95% CI: 1.085-2.673]; p = 0.045). According to the multivariate analysis, only HLHS (OR: 3.856 [95% CI: 1.389-5.863]; p = 0.001), mean pulmonary artery pressure (OR: 1.846 [95% CI: 1.362-2.549]; p = 0.015), and pulmonary vascular resistance index (OR: 1.185 [95% CI: 1.042-1.736]; p = 0.047) were significant risk factors for abnormal parenchymal enhancement.

CONCLUSION

Abnormal hepatic parenchymal enhancement detected through CT is common in Fontan patients. Regular liver function test in conjunction with imaging studies may be considered when following up Fontan patients.

Hepatocellular nodules in vascular liver diseases

Hepatocellular nodules have been recognized in vascular liver diseases for a long time and mostly described and studied in the imaging literature. Some confusions in their identification and overlap in their definitions exist, especially in this specific clinical context. Pathology descriptions report the development of nodular regenerative hyperplasia, large regenerative nodule, and focal nodular hyperplasia, as adaptive responses of the liver parenchyma to the modified blood flow. True neoplastic hepatocellular nodules such as hepatocellular adenoma and hepatocellular carcinoma can also appear, mainly in Budd-Chiari syndrome, and have to be correctly diagnosed. This is more difficult for the radiologist in these diseased livers, leading more frequently to perform liver biopsies. We describe the histology of each type of well-differentiated hepatocellular nodules and provide some clues for their differential diagnosis. A review of the literature gives an historical perspective of the problem and enlightens the frequency and the subtypes of hepatocellular nodules found in the most common vascular liver diseases.

Abdominal imaging findings in adult patients with Fontan circulation

Abstract

The Fontan procedures, designed to treat paediatric patients with functional single ventricles, have markedly improved the patient’s survival into adulthood. The physiology of the Fontan circuit inevitably increases systemic venous pressure, which may lead to multi-system organ failure in the long-term follow-up. Fontan-associated liver disease (FALD) can progress to liver cirrhosis with signs of portal hypertension. Focal nodular hyperplasia-like nodules commonly develop in FALD. Imaging surveillance is often performed to monitor the progression of FALD and to detect hepatocellular carcinoma, which infrequently develops in FALD. Other abdominal abnormalities in post-Fontan patients include protein losing enteropathy and pheochromocytoma/paraganglioma. Given that these abdominal abnormalities are critical for patient management, it is important for radiologists to become familiar with the abdominal abnormalities that are common in post-Fontan patients on cross-sectional imaging.

Teaching points

• Fontan procedure for functional single ventricle has improved patient survival into adulthood.

• Radiologists should be familiar with unique imaging findings of Fontan-associated liver disease.

• Focal nodular hyperplasia-like nodules commonly develop in Fontan-associated liver disease.

• Hepatocellular carcinoma, protein-losing enteropathy, pheochromocytoma/paraganglioma may develop.

Electronic supplementary material

The online version of this article (10.1007/s13244-018-0609-2) contains supplementary material, which is available to authorized users.

The Spectrum of Histologic Findings in Hepatic Outflow Obstruction

CONTEXT

-Cardiac hepatopathy and Budd-Chiari syndrome are 2 forms of hepatic venous outflow obstruction with different pathophysiology but overlapping histologic findings, including sinusoidal dilation and centrilobular necrosis.

OBJECTIVE

-To determine whether a constellation of morphologic findings could help distinguish between the 2 and could suggest the diagnoses in previously undiagnosed patients.

DESIGN

-We identified 26 specimens with a diagnosis of cardiac hepatopathy and 23 with a diagnosis of Budd-Chiari syndrome. Slides stained with hematoxylin and eosin and with trichrome were evaluated for several distinctive histologic findings.

RESULTS

-Features common to both forms of hepatic outflow obstruction included sinusoidal dilation and portal tract changes of fibrosis, chronic inflammation, and bile ductular reaction. Histologic findings significantly more common in cardiac hepatopathy included pericellular/sinusoidal fibrosis and fibrosis around the central vein. Only centrilobular hepatocyte dropout/necrosis was significantly more common in Budd-Chiari, regardless of duration.

CONCLUSIONS

-The finding of pericellular/sinusoidal fibrosis in cardiac hepatopathy compared with Budd-Chiari is not unexpected, given the chronic nature of most cardiac hepatopathy. Portal tract changes are common in both forms of hepatic outflow obstruction and should not deter one from making the diagnosis of hepatic outflow obstruction. Fibrosis along sinusoids and around the central vein may be suggestive of cardiac hepatopathy in biopsies from patients without a prior diagnosis.

Reappraisal of the Role of Portacaval Shunting in the Growth of Patients With Glycogen Storage Disease Type I in the Era of Liver Transplantation

BACKGROUND

Instead of dietary modification, surgical management is considered for correcting growth retardation, poor metabolic control, and hepatocellular adenoma (HCA) in glycogen storage disease (GSD) type I.

METHODS

The records of 55 GSD type I patients were retrospectively reviewed. Thirty-two patients underwent only dietary management (group D) and 23 underwent surgical management (group S). In group S, 17 underwent portacaval shunting (PCS), 13 underwent liver transplantation (LT; 7 underwent both PCS and LT). Height-for-age and body mass index-for-age Z-scores based on World Health Organization data were used to compare growth patterns before and after surgery. Changes in metabolic abnormalities and HCA after operation were also investigated.

RESULTS

Height-for-age Z-scores for group S were higher by an average of 0.377 compared to that for group D. Metabolic abnormalities often disappeared after LT but improved partially after PCS. De novo HCA was detected in 4 patients (13%) from group D, 12 (100%) who underwent PCS, and none who underwent LT. One case of hepatocellular carcinoma and one of hemorrhage from a HCA were noted in group D. Two cases of hepatocellular carcinoma, 2 of hemorrhage, and 1 of necrosis were noted after PCS.

CONCLUSIONS

Surgery yielded greater growth improvement than dietary management. However, after PCS, metabolic abnormalities remained unresolved, and the de novo HCA rate was high. Portacaval shunting can be used to improve growth in GSD type I patients when LT is not possible, but close observation for metabolic abnormalities and HCA is essential.

Liver Transplantation for Budd-Chiari Syndrome With Large Solitary Focal Nodular Hyperplasia of the Liver in a Patient With Essential Thrombocythemia: Case Report. [Corrected]

Budd-Chiari syndrome is a rare condition caused by interrupted hepatic venous outflow in the hepatic veins, inferior vena cava, or right atrium. Reports from the literature have delineated on focal nodular hyperplasia (FNH)-like lesions in association with Budd-Chiari Syndrome. To our knowledge, there are no reports about true FNH lesions in patients with Budd-Chiari Syndrome. Focal nodular hyperplasia develops in disorders with aberrant circulation and vasculature. We report a case of Budd-Chiari syndrome in association with large solitary FNH in a 22-year-old man who was referred to our institution with sudden intermittent right upper quadrant abdominal pain, vomiting, diarrhea with pale stool, decreased appetite, dark urine, and abdominal distention for 15 days. Laboratory investigations revealed anemia, thrombocytosis, and abnormal liver function tests and coagulation profile. Imaging revealed hepatic vein thrombosis, confirming Budd-Chiari syndrome, and a 6.2 × 6.1 × 6.8 cm lesion in segment 8 of the liver. Primary cause of Budd-Chiari syndrome was essential thrombocythemia according to bone marrow biopsy and molecular testing results. The patient was treated medically and underwent transjugular intrahepatic portosystemic shunt insertion. The lesion in segment 8 continued to enlarge. Cadaveric liver transplantation was carried out. On gross and histologic examination of the explanted liver, the lesion was found to be a true FNH.

Multiple hyperplastic nodular lesions of the liver in the Budd-Chari syndrome: a case report and review of published reports

The Budd-Chari syndrome (BCS) is a group of disorders of hepatic vein outflow at various levels from the hepatic veins to inferior vena cave. We describe a 49-year-old man with multiple intrahepatic lesions who had been diagnosed with the BCS. The inferior vena cavography showed hepatic vein occlusion and long-range obstruction of inferior vena cava. The biopsy proved to be hyperplastic nodules, also called large regenerative nodules (LRNs). Both benign regenerative nodules and hepatocellular carcinoma (HCC) appear in patients with BCC; however, published reports about the diagnosis and differential diagnosis are limited. The incidence of HCC in patients with BCS varies greatly depending on geography. This case illustrates that benign nodules can arise in BCS patients. We reviewed published reports and speculated that medical procedures leading to portal perfusion decrease may be associated with the development of these hyperplastic nodules.

Hepatocellular benign tumors-from molecular classification to personalized clinical care

Focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) are benign hepatocellular tumors that develop most frequently in women without cirrhosis. Genomic approaches have identified signaling pathways related to these benign hepatocyte proliferations. FNH, a polyclonal lesion, is characterized by local vascular abnormalities and heterogeneous activation of Wnt/β-catenin and transforming growth factor β signaling. Four major subgroups of HCAs have been identified based on mutations in specific oncogenes and tumor suppressor genes. Each molecular subtype of HCA has been associated with specific pathways, providing new information about benign tumorigenesis. Key features include metabolic alterations (induced by defects in HNF1A), oncogene-induced inflammation (activation of JAK-STAT signaling in inflammatory adenomas), and an association between activation of Wnt/β-catenin signaling and progression of HCAs in hepatocellular carcinomas. Benign hepatocellular tumors can be classified using immunohistochemical analyses. Studies of genotypes and phenotypes of FNH and HCAs have led to the identification of risk factors and improved invasive and noninvasive diagnostic techniques, evaluation of prognosis, and treatment. We review the molecular pathways involved in benign hepatocyte proliferation and discuss how this basic knowledge has been progressively translated into personalized clinical care.

Hepatic pathology after Fontan palliation: spectrum of imaging findings

BACKGROUND

Patients with congenital heart disease corrected by Fontan palliation have chronic liver congestion that commonly progresses to fibrosis and cirrhosis with resultant complications.

OBJECTIVE

To define the hepatic imaging characteristics associated with Fontan circulation.

MATERIALS AND METHODS

A retrospective study was performed in patients who underwent Fontan palliation who had CT or MR examinations including the liver. The liver was evaluated for parenchymal morphology, abnormal enhancement, nodules and imaging findings of fibrosis and cirrhosis.

RESULTS

MRI or CT examinations including the liver were evaluated in 42 Fontan patients. The most common imaging finding was abnormal parenchymal enhancement, present in 38 patients. Hypervascular nodules were present in 13 patients (31%). Imaging findings of cirrhosis were seen in eight patients (19%). One patient with cirrhosis had a large liver mass, subsequently diagnosed as fibrolamellar hepatocellular carcinoma.

CONCLUSION

A high percentage of patients had imaging abnormalities of the liver, chiefly abnormal parenchymal enhancement, which became more apparent as the duration of the Fontan circulation increased. The hypervascular nodules sometimes present had imaging characteristics most closely resembling those of focal nodular hyperplasia. The underlying fibrosis and eventual development of cirrhosis raise the risk of developing hepatocellular carcinoma.

That liver lesion on MDCT in the oncology patient: is it important?

Multidetector-row computed tomography (MDCT) has become the primary imaging test for the staging and follow-up of most malignancies that originate outside of the central nervous system. Technical advances in this imaging technique have led to significant improvement in the detection of metastatic disease to the liver. An unintended by-product of this improving diagnostic acumen is the discovery of incidental hepatic lesions in oncology patients that in the past remained undetected. These ubiquitous, incidentally identified hepatic lesions have created a management dilemma for both clinicians and radiologists: are these lesions benign or do they represent metastases? Naturally, the answer to this question has profound prognostic and therapeutic implications. In this review, guidelines concerning the diagnosis and management of some of the more common hepatic incidental lesions detected in patients with extrahepatic malignancies are presented.

Vascular disorders of the liver: recommendations from the Italian Association for the Study of the Liver (AISF) ad hoc committee

This review summarizes the document elaborated by the Italian Association for the Study of the Liver (AISF) ad hoc committee "Vascular disorders of the liver" on the primary circulatory liver diseases, which include Budd-Chiari syndrome, obstruction of the hepatic portion of the inferior vena cava, portal vein thrombosis, sinusoidal obstruction syndrome (veno-occlusive disease) and hereditary hemorrhagic telangiectasia. A characteristic of the primary circulatory liver diseases is that portal hypertension usually precedes liver dysfunction. Significant overlap exists amongst the diseases and risk factors that predispose patients to the primary circulatory liver diseases, though the pathogenesis of individual diseases varies. Management of the different vascular disorders is very peculiar and often multidisciplinary and patients should be referred to a tertiary referral centre for optimal care.

Rapid development of a hepatocellular carcinoma in isolated thrombosis of hepatic veins (classic Budd-Chiari syndrome): case report and review of literature

Budd-Chiari syndrome and membranous obstruction of the inferior vena cava frequently result in the development of mostly benign hepatic lesions. In cases of membranous obstruction of the inferior vena cava, which is prevalent mostly in the East, these lesions often progress to hepatocellular carcinoma. In contrast, malignant transformation has not yet been recognised in patients with isolated hepatic vein thrombosis. We report the case of a 37-year-old male Caucasian who presented with acute Budd-Chiari syndrome without involvement of the inferior vena cava. Despite porto-caval shunting, a hepatocellular carcinoma developed within several months. Three hepatic lesions were treated by radiofrequency thermal ablation until liver transplantation was performed. This report emphasises the possibility of malignant transformation of regenerative nodules in patients with disturbed hepatic perfusion in general. Physicians must be aware of this when assessing regenerative nodules, especially as no unambiguous predictors for the development of hepatocellular carcinoma have been identified so far.

Radiological and histopathological manifestations of hepatocellular nodular lesions concomitant with various congenital and acquired hepatic hemodynamic abnormalities

Congenital and acquired hepatic hemodynamic abnormalities are classified into four categories: hepatic arterial inflow disorder, portal vein inflow disorder, hepatic vein outflow disorder, and presence of a third inflow to the liver. Although their detailed etiology is not fully understood, these hepatic hemodynamic abnormalities may cause the formation of hepatocellular nodules. Recent advances in imaging modalities now enable visualization of these hepatocellular nodules concomitantly with the identification of various congenital and acquired hemodynamic abnormalities. Most of these nodular lesions are benign hyperplastic nodules, such as focal nodular hyperplasia, nodular regenerative hyperplasia, and other types of regenerative nodules. However, neoplastic nodules such as hepatic adenoma and hepatocellular carcinoma may also occur in conjunction with hepatic hemodynamic abnormalities. Distinguishing neoplastic nodules, especially malignant liver tumors, from hyperplastic nodules is important. Detection of intranodular Kupffer cells with superparamagnetic iron oxide enhanced magnetic resonance imaging is a key indicator that a nodule is regenerative rather than neoplastic.

Regenerative nodules in patients with chronic Budd-Chiari syndrome: a longitudinal study using multiphase contrast-enhanced multidetector CT

OBJECTIVE

Our aim was to evaluate the serial evolution of regenerative nodules in patients with Budd-Chiari syndrome (BCS) treated with portal-systemic shunts, using multiphasic multidetector computed tomography (MDCT).

MATERIALS AND METHODS

Five patients each underwent three MDCT exams over an extended period ranging from 36 to 42 months. Two radiologists in consensus retrospectively reviewed each exam for each patient. Individual nodules were grouped according to size (size I: nodules with diameter < or =15 mm; size II: >15 mm but <30 mm; size III: > or =30 mm), pattern of enhancement (A: homogeneously hypervascular or B: with central scar), and segmental location. Four nodules classified as size II, which increased in size over time, were needle-biopsied.

RESULTS

We detected 61 nodules at the first exam, 66 nodules at the second exam (7 nodules disappeared and 12 new nodules), and 85 nodules at the third exam (8 disappeared and 27 new) for a total of 212 findings. Nodules were mostly found in the right hepatic lobe. Fourteen of the 15 nodules that disappeared over time were size I and enhancement pattern A. At unenhanced MDCT, 204 (96%) of the 212 findings were isodense. Overall, 100 nodules, including the 61 initially detected, were considered newly diagnosed; of these 84 (84%) were size I and pattern A. Of 57 nodules considered size I and pattern A at the first or second exam, 24 (42%) changed to pattern B at the third exam and either size II (n=18) or III (n=6). The four biopsied nodules were each confirmed as benign regenerative nodule. No patient developed HCC at 5-year follow-up period.

CONCLUSION

Hepatic nodules in BCS patients not only increase in number over time but may also increase in size and develop a central scar.

Case report of a focal nodular hyperplasia-like nodule present in cirrhotic liver

An 81-year-old female was referred to Sapporo Medical University Hospital because of a nodular lesion 20 mm in diameter found in the liver S8 during follow-up for type C liver cirrhosis. Abdominal ultrasonography showed a capsule-like structure, and contrast computed tomography revealed hypervascularity at the early phase and inner pooling of the contrast medium with ring enhancement at the late phase. Magnetic resonance T2-weighted imaging (T2WI) demonstrated a hyperintensity nodule with further hyperintensity signals in some parts of the nodule, and the signal pattern differed from that of typical fibrosis. SPIO-magnetic resonance imaging showed partial hypointensity signals by T2WI, which indicated the presence of Kupffer cells. Angiography did not show a spoke-wheel pattern. The results by imaging modalities indicated that the nodule was atypical for hepatocellular carcinoma (HCC) and focal nodular hyperplasia (FNH), and liver nodule biopsy was performed for histological diagnosis. Compared with the background liver, the nodule revealed high cellular density, cellular dysplasia at the periphery, a pseudo-crypt structure and irregular hepatic cord arrangement in some parts of the nodule. Among them, there was immature fibrous tissue containing arterioles with muscular hypertrophy. There has been no report of well-differentiated HCC with a central scar, and this case was presumed to be an FNH-like nodule with dysplasia physically associated with cirrhotic tissue.

Efficacy and safety of 6-thioguanine in the management of inflammatory bowel disease

OBJECTIVE

6-Thioguanine has been used as an alternative immunomodulator in the treatment of inflammatory bowel disease but data on its efficacy and safety are limited. The aim of this study was to analyse our experience of the efficacy and safety of 6-thioguanine in inflammatory bowel disease.

MATERIAL AND METHODS

Patients attending the inflammatory bowel disease clinic who were started on 6-thioguanine therapy were included in this prospective observational study. Indications for initiating 6-thioguanine therapy and other related clinical, pharmacological and laboratory parameters prior to and during therapy were recorded to determine the efficacy and safety of 6-thioguanine.

RESULTS

A total of 40 patients were treated with 6-thioguanine, 28 with Crohn's disease, 10 with ulcerative colitis and 2 with indeterminate colitis, at a fixed daily dose of 40 mg and continued for a median duration of 34 weeks (range 2-90 weeks). The indications for 6-thioguanine therapy included previous clinical resistance to thiopurine analogues (n=21), intolerance to thiopurine analogues (n=8) and de novo 6-thioguanine use in steroid refractory disease (n=11). Disease remission was reached in 44%, 73% and 89% of these patient groups at 3, 6 and 12 months, respectively. Inflammatory markers and steroid use were significantly lower during 6-thioguanine therapy compared with in the period before therapy. Therapy was discontinued in 13 patients (33%), mainly because of thrombocytopenia and associated hepatotoxicity.

CONCLUSIONS

6-Thioguanine is a useful addition to treatment in inflammatory bowel disease but the frequent occurrence of hepatotoxicity limits its routine use.

Leberparenchymknoten bei pathologischer hepatischer Vaskularisation/Perfusion

Nodular regenerative hyperplasia (NRH) is characterized by a non-cirrhotic micronodular transformation of the liver parenchyma. It is based on the obliteration of small portal veins. Macroregenerative nodules (MRN) develop in areas of favourable blood flow in otherwise hypoperfused liver tissue. Hypoperfusion is caused by obliteration of liver veins and/or large portal veins with the subsequent atrophy or extinction of parenchyma. The hyperperfused and sometimes rapidly growing MRN might simulate a malignant tumor in CT and MRT. Morphologically, MRN resemble FNH. In contrast to hepatocellular adenoma, they show a more or less nodular architecture with fibrous septa and ductular structures. NRH and cases of MRN without cirrhosis can indicate an extrahepatic/systemic disease causing altered liver perfusion. MRN in liver cirrhosis must be differentiated from dysplastic nodules and highly differentiated hepatocellular carcinoma by cytological and microarchitectural criteria. Focal nodular hyperplasia (FNH) can imitate liver cirrhosis, steatohepatitis, cholangitis or chronic hepatitis, if biopsy material does not include normal perilesional liver tissue. Telangiectatic FNH might resemble classic hepatocellular adenoma. Neoductular structures and septation argue for this rare subtype of FNH. Neoductular transformation of hypoperfused liver parenchyma might imitate cholangioma or cholangiocarcinoma.

Budd-Chiari syndrome

Budd-Chiari syndrome is a spectrum of disease states, including anatomic abnormalities and hypercoagulable disorders, resulting in hepatic venous outflow occlusion. Clinical manifestations observed in the majority of patients include hepatomegaly, right upper quadrant pain, and abdominal ascites. This article outlines the approach to clinical diagnosis and supportive medical therapy in patients who have BCS and reviews the clinical data supporting surgical shunting and liver transplantation as viable treatment options in this patient population.

Hepatobiliary pathology

PURPOSE OF REVIEW

This review highlights recent publications on hepatobiliary pathology concerning several unusual types of hepatitis, fatty liver disease, disorders of the biliary tree and other topics that have a substantial impact on liver biopsy interpretation.

RECENT FINDINGS

In the outbreak of severe acute respiratory syndrome (SARS), many patients had abnormalities in liver function tests. Liver biopsy findings in three cases were reported that showed a generic picture of hepatitis, with exceptionally increased mitotic activity. The role of portal myofibroblasts in cirrhosis was examined in several studies. A newly described lesion, isolated ductular hyperplasia (IDH) was found in patients with prolonged abnormalities of liver function tests of uncertain origin. Hyperplastic, well-differentiated bile ductules were seen on liver biopsy in the absence of any identifiable biliary disease. Hereditary hemochromatosis is now a complex entity with various clinicopathological forms based on mutations in the HFE gene and other iron-homeostatic genes such as transferrin receptor 2 and ferroportin 1. In some of these heritable forms of primary iron overload, stainable iron is present in both hepatocytes and Kupffer cells. After liver transplantation, differentiating recurrent HCV infection from acute rejection on liver biopsy is problematic, with exceptionally low inter- and intra-observer reliability shown in one study.

SUMMARY

The hepatitis associated with the SARS coronavirus, Isolated Ductular Hyperplasia in patients with liver function test abnormalities and other topics with pathologic relevance are reviewed.

Update on the classification, assessment of prognosis and therapy of Budd–Chiari syndrome

Budd-Chiari syndrome (BCS) occurs as a result of obstruction of hepatic venous outflow at any level from the small hepatic veins to the junction of the inferior vena cava with the right atrium. Diagnosis can be difficult because of the wide spectrum of presentation of the disease and the varying severity of liver damage. The traditional classification of BCS--as fulminant, acute or chronic--is not prognostically useful. This makes assessing the benefit of therapy difficult, especially as there is no evidence from randomized studies. This article highlights advances in the prognosis and therapy of BCS. Identification of the site of venous obstruction has a major effect on prognosis. Portal-vein thrombosis occurs in 20-30% of cases, and acute presentation of BCS reflects an acute or chronic syndrome in 60% of BCS cases. BCS can be diagnosed and treated on a single occasion in the setting of the radiology department, with hepatic venography, transjugular liver biopsy, retrograde CO2 portography and inferior vena cava pressure measurements performed simultaneously with therapies such as dilation or stenting of webs in the inferior vena cava or hepatic veins, and placement of transjugular intrahepatic portosystemic shunts. Disruption of a portal vein thrombus can also be done during the same session. Surgical shunts have been superseded by the use of transjugular intrahepatic portosystemic shunts. Liver transplantation is reserved for fulminant and progressive chronic forms of BCS. Anticoagulation therapy must be used routinely, before and after specific therapy, regardless of whether a thrombophilic disorder is diagnosed.