Nodular regenerative hyperplasia: Evolving concepts on underdiagnosed cause of portal hypertension

A rare case of liver regenerative and non-neoplastic lesion resembling a well-differentiated hepatocellular carcinoma

BACKGROUND

Nodular regenerative hyperplasia (NRH) is a rare disease that presents pathologically as diffuse hepatic nodules without fibrous septa. It is believed to be caused by vasculopathy against a background of various systemic diseases, such as hematologic, autoimmune, and drug-induced diseases, with various symptoms. In spite of the recent imaging advances, various atypical cases of nodular lesions are observed in daily clinical practice. Cases that do not completely meet these criteria are referred to as -like or -similar lesions in clinical situations, making it difficult to understand their pathogenesis. We present a case in which two hepatic nodular lesions were noted and difficult to differentiate from malignancy preoperatively. The lesions were laparoscopically resected and a pathological diagnosis with non-neoplastic liver regenerative nodules resembling NRH was made.

CASE PRESENTATION

A 49-year-old man with no alcohol or drug intake and no past medical history was identified as having liver tumors on screening examination without any symptoms. Contrast-enhanced computed tomography (CT) showed two hepatic tumors; approximately 2-cm tumors at S7 and S8. Gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) revealed fat inclusions in their contents. Ethoxybenzyl (EOB) uptake was also observed during the hepatobiliary phase. Based on preoperative examinations, we suspected well-differentiated hepatocellular carcinoma (HCC) and performed laparoscopic S7/8 partial resection for these lesions. Macroscopically, the resected specimens showed a non-cirrhotic yellowish-cut surface containing brownish, ill-defined lesions with irregular borders. Microscopically, these lesions showed zonal necrosis, congestion, and aggregation of hemosiderin-laden macrophages around the central vein. In these areas, the fatty deposition of hepatocytes was lower than that in the surrounding background hepatocytes. Histopathologically, neither neoplastic nor hyperplastic lesions were observed, and he was diagnosed as regenerative hepatic change with centrilobular necrosis.

CONCLUSIONS

Considering the pathological results, these lesions were thought to be a type of NRH-like lesion with possible hepatic vessel disorder. However, the lesion's cause and classification was difficult to determine. The accumulation of these regenerative changes accompanying fatty liver is needed to clarify the mechanism and its clinical significance.

Value of contrast-enhanced ultrasound for vascular diseases of the liver - current indications and open questions

Contrast-enhanced ultrasonography (CEUS) is a widely available and well-tolerated technique that can expand the diagnosis of a variety of vascular liver diseases. This paper presents an overview of the current possibilities of the use of CEUS in vascular liver diseases. Particularly where Doppler sonography has technical limitations, CEUS provides additional opportunities to visualize vascular thrombosis and other obstructions restricting blood flow. When CT or MRI contrast agents cannot be used because of severe allergy or renal insufficiency, CEUS can be a valuable diagnostic alternative and has demonstrated comparable diagnostic performance in at least some vascular liver diseases, such as portal vein thrombosis. In addition, CEUS works without radiation and, therefore, might be particularly suitable for young patients and children. This may be useful, for example, in congenital disorders such as persistent umbilical vein or preduodenal portal vein. Vascular liver disease is rare and comprehensive data are still lacking, but the available literature provides promising insights into potential new ways to study vascular liver disease. Although most studies are based on small sample sizes or even case reports, the high diagnostic utility is undisputed.

Congenital extrahepatic portosystemic shunt masquerading as chronic portal vein thrombosis: A case report

INTRODUCTION AND IMPORTANCE

Congenital extra hepatic portosystemic shunt (CEPS) is a rare vascular malformation in which splanchnic and portal blood is shunted into the systemic circulation eluding the liver. Type 1 CEPS is sometimes difficult to differentiate from pathologies such as chronic portal veinthrombosis as the portal vein may not be visualized in either entities.

CASE PRESENTATION

A 3-year-old male child with a week of abdominal pain was diagnosed with chronic portal vein thrombosis in an out-of-hospital setting. Repeat abdominal ultrasound was done at our institution and we were able to visualize termination of the portal vein to the suprarenal infra-hepatic inferior vena cava with an end to side pattern and a focal hypoechoic hepatic lesion at segment eight of the liver. There was no evidence of cavernous transformation or sign of portal hypertension. Subsequently, tri-phasic computed tomography revealed similar findings, with the portal vein terminating at the suprarenal inferior vena cava. The focal hepatic lesion showed peripheral contrast enhancement in the arterial phase and appeared as a central non-enhancing area with evidence of homogeneous enhancement on the subsequent sequences.

CLINICAL DISCUSSION

Type 1 CEPS can be easily confused with chronic portal vein thrombosis as the portal vein may not be visible and the hepatic artery shows compensatory enlargement in both entities. However, portal vein thrombosis is usually associated with underlying predisposing factors and can result in the development of secondary signs of portal hypertension and cavernous transformation which are critical to distinguish it from CEPS.

CONCLUSION

Chronic portal vein thrombosis is a great mimicker that should be distinguished from CEPS on ultrasound. A meticulous scan with color flow is helpful to scrutinize vascular anatomy, identify findings associated with CEPS such as hepatic lesions, and exclude signs of chronic portal vein thrombosis.

Spectrum of Liver Pathology in Dyskeratosis Congenita

Dyskeratosis congenita (DC) is a rare multisystemic disorder associated with defective telomere maintenance. Frequent clinical manifestations of DC include reticular skin pigmentation, dystrophic nails, oral leukoplakia, and bone marrow failure. Hepatic disturbances are reported to occur in 7% of DC patients. This study aimed to evaluate the histopathologic spectrum of hepatic involvement in this disorder. DC patients with liver tissue in the pathology database at Boston Children's Hospital from 1995 to 2022 were identified. Clinical and pathologic information was documented. Thirteen specimens from 11 DC patients were included (M:F = 7:4; median age at the time of liver tissue evaluation: 18 y). DC-associated gene mutations were identified in 9 patients; TERF1-interacting nuclear factor 2 ( TINF2) was the most frequently represented gene mutation, seen in 4 patients. All patients had bone marrow failure, whereas dystrophic nails, cutaneous abnormal pigmentation, and oral leukoplakia were noted in 73%, 64%, and 55% of patients, respectively. Seven patients underwent bone marrow transplants before biopsy/autopsy (median interval of 45 mo). Histologically, 3 of 4 patients who presented with portal hypertension showed noncirrhotic changes (nodular regenerative hyperplasia and/or obliterative portal venopathy), whereas prominent central and sinusoidal fibrosis was noted in patients with intrahepatic shunting and those showing features of chronic passive congestion. All cases showed hepatocyte anisonucleosis. One patient developed hepatic angiosarcoma, and another 1 had colorectal adenocarcinoma metastatic to the liver. DC patients show heterogeneous histologic findings in their liver. The findings of noncirrhotic portal hypertension, intrahepatic shunting, and angiosarcoma suggest vascular functional/structural pathology as a possible unifying etiology of hepatic manifestations of DC.

Evidence for Alloimmune Sinusoidal Injury in De Novo Nodular Regenerative Hyperplasia After Liver Transplantation

Posttransplant nodular regenerative hyperplasia (NRH) mostly remains unexplained. Microvascular injury due to antibody-mediated rejection (AMR) is suspected, but lack of donor specific antibody (DSA) testing makes it difficult to prove. Centered around a 1-year period of routine DSA testing, concomitant protocol, and indicated posttransplant liver biopsies (LB), recipients with NRH (n = 18) were compared with a matched control group (n = 36). All index, previous, and subsequent LB were reviewed. Both groups were similar in terms of demographics, timing of index LB, and DSA. In the index LB, the NRH group had higher sinusoidal C4d positivity (p = 0.029) and perisinusoidal fibrosis (p = 0.034), both independently associated with NRH (p = 0.038 and 0.050, respectively). Features of "possible" chronic AMR were detected in 28.5% of the NRH group without a known cause and 0% of the control group (p = 0.009). The NRH group had more preceding indicated LB with increased incidence of rejection and biliary obstruction pattern. In the follow-up histology, overall, sinusoidal and portal C4d positivity, sinusoidal microvasculitis, and perisinusoidal fibrosis were also higher (all p < 0.050). In conclusion, we provide evidence towards the hypothesis that some cases of posttransplant NRH are related to preceding active and persistent AMR. Large multicenter studies with protocol DSA testing are required to confirm.

Generalized crystal-storing histiocytosis with noncirrhotic portal hypertension: an autopsy case report

Crystal-storing histiocytosis (CSH) is a rare disease associated with the accumulation of histiocytes containing crystalline matter within their cytoplasm. Herein, we present the case of a female patient who was diagnosed with Tolosa-Hunt syndrome at 45 years of age and idiopathic retroperitoneal fibrosis when she was 48 years. She developed portal hypertension (PH), but did not present with cirrhosis; as such, the cause of PH was not identified. Her PH gradually worsened when she was 54 years, and at the age of 60 years, she died from an acute subdural hematoma. Autopsy revealed retroperitoneal fibrosis with severe fibrosis extending around the hepatic veins and into the porta hepatis. Histologically, the retroperitoneal tissue showed a dense infiltrate of eosinophilic histiocytes with crystal structures in the cytoplasm, which was pathologically diagnosed as CSH. Nodular regenerative hyperplasia was observed in the liver parenchyma, whereas cirrhosis was not. In the present case, CSH caused fibrosis, which was believed to be the cause of PH. In addition, we considered that nodular regenerative hyperplasia caused by the altered hepatic blood flow due to treatment of gastric varices contributed to worsening PH. Hence, CSH should be considered as an underlying disease in noncirrhotic portal hypertension.

Nodular Regenerative Hyperplasia Is Not a Rare Condition After Liver Transplantation: Incidence, Predictive Factors, and Impact on Survival

BACKGROUND

The objectives of this study were to evaluate incidence and to identify the risk factors of occurrence and the predictive factors of symptomatic forms of nodular regenerative hyperplasia (NRH) after liver transplantation (LT).

METHODS

To identify risk factors of NRH following LT, we included 1648 patients transplanted from 2004 to 2018 and compared the patients developing NRH after LT to those who did not. To identify predictive factors of symptomatic NRH, we selected 115 biopsies displaying NRH and compared symptomatic to asymptomatic forms. Symptomatic NRH was defined as the presence of ascites, esophageal varices, hepatic encephalopathy, portal thrombosis, retransplantation, or death related to NRH.

RESULTS

The incidence of NRH following LT was 5.1%. In multivariate analysis, the independent factor of developing NRH after LT was the donor's age (odds ratio [OR] = 1.02; confidence interval, 1.01-1.03; P = 0.02). Symptomatic forms occurred in 29 (25.2%) patients: 19 (16.5%) patients presented with ascites, 13 (11.3%) with esophageal varices, 4 (3.5%) with hepatic encephalopathy, and 8 (7%) with portal thrombosis. The median period before the onset of symptoms was 8.4 (1.5-11.3) y after LT. The spleen size at diagnosis/before LT ratio (OR = 12.5; 114.17-1.37; P = 0.0252) and thrombectomy during transplantation (OR = 11.17; 1.48-84.11; P = 0.0192) were associated with symptomatic NRH in multivariate analysis.

CONCLUSIONS

NRH following LT is frequent (5.1%) and leads to symptomatic portal hypertension in 25.2% of patients. Using older grafts increases the risk of developing NRH after LT. Clinicians should screen for signs of portal hypertension, particularly in measuring spleen size.

Liver disease accompanied by enteropathy in common variable immunodeficiency: Common pathophysiological mechanisms

Common variable immunodeficiency (CVID) is one of the inborn errors of immunity that have the greatest clinical impact. Rates of morbidity and mortality are higher in patients with CVID who develop liver disease than in those who do not. The main liver disorder in CVID is nodular regenerative hyperplasia (NRH), the cause of which remains unclear and for which there is as yet no treatment. The etiology of liver disease in CVID is determined by analyzing the liver injury and the associated conditions. The objective of this study was to compare CVID patients with and without liver–spleen axis abnormalities in terms of clinical characteristics, as well as to analyze liver and duodenal biopsies from those with portal hypertension (PH), to elucidate the pathophysiology of liver injury. Patients were divided into three groups: Those with liver disease/PH, those with isolated splenomegaly, and those without liver–spleen axis abnormalities. Clinical and biochemical data were collected. Among 141 CVID patients, 46 (32.6%) had liver disease/PH; 27 (19.1%) had isolated splenomegaly; and 68 (48.2%) had no liver–spleen axis abnormalities. Among the liver disease/PH group, patients, even those with mild or no biochemical changes, had clinical manifestations of PH, mainly splenomegaly, thrombocytopenia, and esophageal varices. Duodenal celiac pattern was found to correlate with PH (p < 0.001). We identified NRH in the livers of all patients with PH (n = 11). Lymphocytic infiltration into the duodenal mucosa also correlated with PH. Electron microscopy of liver biopsy specimens showed varying degrees of lymphocytic infiltration and hepatocyte degeneration, which is a probable mechanism of lymphocyte-mediated cytotoxicity against hepatocytes and enterocytes. In comparison with the CVID patients without PH, those with PH were more likely to have lymphadenopathy (p < 0.001), elevated β₂-microglobulin (p < 0.001), low B-lymphocyte counts (p < 0.05), and low natural killer-lymphocyte counts (p < 0.05). In CVID patients, liver disease/PH is common and regular imaging follow-up is necessary. These patients have a distinct immunological phenotype that may predispose to liver and duodenal injury from lymphocyte-mediated cytotoxicity. Further studies could elucidate the cause of this immune-mediated mechanism and its treatment options.

Identification and clinical significance of nodular regenerative hyperplasia in primary sclerosing cholangitis

BACKGROUND AND AIM

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by inflammation and fibrosis of intrahepatic and extrahepatic bile ducts. PSC is frequently associated with inflammatory bowel disease (IBD). Nodular regenerative hyperplasia (NRH) can occur in IBD with the use or even in the absence of thiopurine treatment. We aimed to study the significance of the presence of NRH and obliterative portal venopathy (OPV), both causes of non-cirrhotic portal hypertension (NCPH), in patients having PSC.

METHODS

Patients with PSC and concurrent NRH on liver biopsy were identified from the digital pathology database covering the period 2003-2019. Evaluation of liver biopsy and the original diagnoses were confirmed on review based on standard histological features diagnostic for NRH and OPV. Clinical and laboratory data were obtained from electronic medical records.

RESULTS

Thirty-one patients (21 male, 10 female; median age at biopsy 40.1 years) were included in the study. Twelve (38.7%) patients had OPV in addition to NRH on the liver biopsy. Nineteen (61.2%) patients had IBD including 11 with Crohn's disease (CD), 7 with ulcerative colitis (UC), and 1 with indeterminate colitis. Thirteen (41.9%) patients had evidence of portal hypertension, 10 (32.2%) with esophageal varices, 4 (12.9%) with history of variceal bleeding, 6 (19.3%) with ascites, and 14 (12.9%) with splenomegaly. Eleven (35.4%) patients had a cirrhotic-appearing liver on imaging. Twelve (38.7%) patients had a history of prior or current thiopurine use.

CONCLUSIONS

The current study suggests that NRH with or without OPV independently occurs in patients having PSC and may lead to NCPH, even in the absence of concurrent IBD and/or thiopurine therapy.

Liver abnormalities in Turner’s syndrome – the importance of estrogen replacement

Turner syndrome is one of the most frequently reported sex chromosomal abnormalities, affecting approximately 40 in every 100 000 live female births. The underlying chromosomal alteration is the complete or partial loss of X chromosome or mosaicism. Because of primary ovarian insufficiency, the synthesis of estrogen hormones is compromised, and patients require hormone substitution. Apart from the phenotypical presentation (short stature, primary amenorrhea), the effects of ovarian insufficiency can affect diverse organ systems (such as cardiovascular, endocrine, and lymphatic systems). Hepatobiliary pathology can present on a broad spectrum: from mild asymptomatic hypertransaminasemia to marked architectural changes. Estrogen hormone replacement therapy in these patients can improve the perturbations of laboratory values and can attenuate the progression of hepatic structural changes. Moreover, providing sufficient estrogen replacement has numerous benefits for other conditions of the patients as well. Both the all-cause mortality and deaths from cardiovascular complications are greatly increased in Turner syndrome, and hormone replacement might contribute to the decreased incidence of these events. The diagnostics of Turner syndrome are outside the scope of our paper, and we briefly discuss the cardiovascular complications because many the liver involvement partially involves alterations of vascular origin. Though we sought to highlight the importance of proper hormone replacement therapy, we did not attempt to write a comprehensive recommendation for exact treatment protocols. We provided an overview of preferred therapeutic approaches, as the treatment should be tailored according to the individual patient’s needs.

Noncirrhotic Portal Hypertension after Trastuzumab Emtansine in HER2-positive Breast Cancer as Determined by Deep Learning-measured Spleen Volume at CT

Background Trastuzumab emtansine (T-DM1) is an antibody-drug conjugate approved for use in human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Case reports have suggested an association between T-DM1 and portal hypertension. Purpose To evaluate the association of T-DM1 therapy with spleen volume changes and portal hypertension on CT scans and clinical findings compared with lapatinib and capecitabine therapy. Materials and Methods Patients with HER2-positive breast cancer who were administered at least two cycles of T-DM1 or lapatinib and capecitabine (controls) in a tertiary institution from 2001 to 2020 and who underwent CT before initial treatment and at least once during treatment were retrospectively enrolled. Spleen volume changes and the signs of portal hypertension (gastroesophageal varix [GEV], spontaneous portosystemic shunt [SPSS], and ascites) were evaluated at contrast-enhanced CT. Patients were followed until treatment ended or for 2 years after the start of treatment. Spleen volume changes were measured with a deep learning algorithm and evaluated by using a linear mixed model. The incidences of splenomegaly and portal hypertension were compared between the T-DM1 and control groups by using a χ² test or Fisher exact test. Results The T-DM1 group included 111 patients (mean age, 54 years ± 11 [SD]; 111 women) and the control group included 122 patients (mean age, 50 years ± 9; 121 women). Spleen volume progressively increased with T-DM1 therapy but was constant in the control group (104% ± 5 vs -1% ± 6 at the 33rd treatment cycle, respectively; P < .001). Incidences of splenomegaly (46% [51 of 111] vs 3% [four of 122] of patients; P < .001), GEV (11% [12 of 111] vs 1% [one of 122] of patients; P < .001), and SPSS (27% [30 of 111] vs 1% [one of 122] of patients; P < .001) were higher in the T-DM1 group than in the control group. Conclusion Trastuzumab emtansine therapy was associated with noncirrhotic portal hypertension at CT, with higher incidences of splenomegaly, gastroesophageal varix, and spontaneous portosystemic shunt than those with lapatinib and capecitabine therapy. © RSNA, 2022 Online supplemental material is available for this article.

Autoimmune liver diseases in systemic rheumatic diseases

Systemic rheumatic diseases (SRDs) are chronic, inflammatory, autoimmune disorders with the presence of autoantibodies that may affect any organ or system. Liver dysfunction in SRDs can be associated with prescribed drugs, viral hepatitis, alternative hepatic comorbidities and coexisting autoimmune liver diseases (AILDs), requiring an exclusion of secondary conditions before considering liver involvement. The patterns of overlap diseases depend predominantly on genetic determinants with common susceptible loci widely distributing in both disorders. In AILDs, it is important to identify the overlapping SRDs at an early stage since such a coexistence may influence the disease course and prognosis. Commonly co-occurring SRDs in AILDs are Sjögren syndrome (SS), rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) in autoimmune hepatitis (AIH), and SS, RA or systemic sclerosis in primary biliary cholangitis. Owing to different disease complications and therapies, it is imperative to differentiate between SLE liver involvement and SLE-AIH overlap disease. Therapeutic options can be personalized to control coexisting conditions of liver autoimmunity and rheumatic manifestations in AILD-SRD overlap diseases. The collaboration between hepatologists and rheumatologists can lead to significant advances in managing such a complex scenario. In this review, we provide a comprehensive overview on coexisting AILDs in different SRDs and the therapeutic approach in managing these overlap diseases.

Outcomes of idiopathic versus secondary nodular regenerative hyperplasia of the liver: A longitudinal study of 167 cases

BACKGROUND

Nodular regenerative hyperplasia (NRH) is a rare condition characterized clinically by the development of non-cirrhotic portal hypertension. NRH is the histopathological result in the liver of various systemic disease processes including autoimmune disorders, haematological malignancies and medications. However, natural history of this condition has been limited to small case series while patient outcomes pertaining to different aetiologies of NRH are largely unknown.

METHODS

A retrospective cohort of consecutive patients diagnosed with pathology-confirmed NRH at Mayo Clinic between 2002 and 2017 was identified. The histological diagnosis of NRH was determined by expert liver pathologists. Patients with metastatic liver disease, history of liver transplantation or younger than 18 were excluded. Potential aetiologies of NRH were classified as haematological, rheumatological, drug-associated, miscellaneous or idiopathic. Long-term mortality was analysed using Kaplan-Meier estimation and Cox regression models.

RESULTS

One hundred and sixty-seven consecutive patients with pathology-confirmed NRH were analysed over a 15-year period and followed for a median time of 50 months (1-306 months). The mean age at diagnosis was 53 years. No aetiology or risk factor for NRH was identified in the majority of patients (94, 56.3%), whereas an associated, possibly causal, condition was found in 73 patients (secondary NRH). The most common presenting feature was elevated liver tests (80%), but no significant differences in laboratory tests were seen based on aetiology of NRH. Compared to idiopathic NRH, those with an identified cause had a higher rate of splenomegaly at presentation (54% vs. 27%, p = 0.002). Portal hypertension-related complications at diagnosis were common, with ascites present in one-third of patients. Overall transplant-free survival was 63% at 5 years. Median survival in idiopathic NRH was 9.4 years compared to 7.3 years in secondary NRH. Age, renal function and volume status at presentation were significantly associated with survival; however, MELD score was not.

CONCLUSIONS

The rates of liver-related complications and mortality in NRH are low, and only a small number of patients ultimately require liver transplantation. Most patients do not have an identified risk factor or aetiology for NRH, and liver-related outcomes do not appear to differ based on associated, possibly causal, conditions.

Nodular Regenerative Hyperplasia of the liver in Juvenile Dermatomyositis

BACKGROUND

We present two cases of Nodular Regenerative Hyperplasia (NRH) associated with Juvenile Dermatomyositis (JDM).

CASE PRESENTATION

Case 1: A nine-year-old Caucasian male with refractory JDM and anti-NXP2 autoantibodies was diagnosed at age two. Over seven years, he developed arthritis, dysphagia, dysphonia, severe calcinosis, and colitis. Complications included recurrent cellulitis, infections, and hepatosplenomegaly. Multiple medications were chronically used, including prednisone, methotrexate, azathioprine, cyclophosphamide, mycophenolate mofetil, rituximab, tacrolimus, etanercept, abatacept, infliximab, and tocilizumab. Case 2: A 19-year-old Asian female with chronically active JDM and anti-MDA5 autoantibodies was diagnosed at age 15. Symptomatology included ulcerative skin lesions, Raynaud's phenomenon with digital ulcers, arthritis, interstitial lung disease with pulmonary hypertension, and calcinosis. Medications included chronic use of prednisone, methotrexate, abatacept, cyclophosphamide, mycophenolate mofetil, rituximab, tofacitinib, and sildenafil. In both patients, clinical symptomatology was not suggestive of liver disease or portal hypertension, but laboratory studies revealed elevated serum transaminases with progressive thrombocytopenia and no active liver-associated infections. The first patient's liver ultrasound showed coarse hepatic texture with mild echogenicity, splenomegaly, and portal hypertension. The second patient's liver ultrasound was normal, but elastography indicated increased stiffness. Liver biopsy confirmed NRH in both patients.

CONCLUSIONS

It is difficult to recognize NRH in JDM, as it often presents with elevated transaminases which may be mistaken for JDM muscle flare, corticosteroid-related fatty liver, or medication-related transaminitis. NRH has been associated with several medications used to treat JDM, including methotrexate, azathioprine, and cyclophosphamide, which should be discontinued if NRH develops. Providers should consider NRH in JDM patients with severe, refractory disease who have persistently elevated transaminases and persistent thrombocytopenia.

Evaluation of Liver Histopathological Findings of Coronavirus Disease 2019 by Minimally Invasive Autopsies

AIM

The severe acute respiratory syndrome coronavirus 2 outbreak resulted in severe health impact with the loss of many lives across the world. Pulmonary parenchyma suffers the most from the brunt of the infection. However, evidence suggested a systemic involvement during the course of illness. Information on morphological changes of the liver is sparse in the literature. We aimed to evaluate the pathological findings in the liver by minimally invasive autopsies.

METHODS

Postmortem core biopsies of the liver obtained from patients who succumbed to coronavirus disease 2019 disease were studied. Demographic findings, comorbidities, and relevant laboratory tests were collected. Detailed histopathological changes were assessed.

RESULTS

Liver function tests were available in 40 cases, and it was deranged in 80% cases. A spectrum of histological changes was observed. Macrovesicular steatosis and nonspecific portal inflammation of mild degree were the common morphological changes. Features suggestive of vascular alteration were noted in more than half of the cases. These included increased portal vein branches, irregular luminal dilation, and herniation of portal veins into the periportal hepatocytes. In addition, we observed morphological changes attributed to terminal shock-related changes.

CONCLUSION

The present study results highlight that liver parenchyma changes may be related to multiple pathogenic mechanisms. The presence of vascular alteration in portal tracts suggests derangement of hepatic vasculature related to systemic hypercoagulable state induced by the viral infection. It remains to be established if the histological changes are related to direct viral insult or to the systemic response caused by the viral attack.

Trastuzumab Emtansine-Induced Nodular Regenerative Hyperplasia: Is Dose Reduction Enough as a Preventable Measure?

INTRODUCTION

Trastuzumab emtansine (T-DM1) is a novel antibody-drug conjugate targeting the human epidermal growth factor receptor 2, used in some recurrent metastatic cancers. It was linked to modest increases in serum aminotransferase elevations and bilirubin. More recently, some cases of noncirrhotic portal hypertension have been described in patients on long-term T-DM1. The underlying liver condition is usually nodular regenerative hyperplasia (NRH) with elements of sinusoidal obstruction.

CASE REPORT

We report the case of a 52-year-old woman who started T-DM1 therapy for recurrent metastatic lung adenocarcinoma. Although a progressive reduction in lung nodules was noticed, there was a new-onset cytocholestasis and elevation in bilirubin. A reduction in platelet count was also apparent over several months during the T-DM1 therapy. Liver biopsy revealed NRH and so the dose of T-DM1 was reduced. Thereafter, the patient had normalization of liver tests and platelet count. T-DM1 was continued for more than 9 months with no signs of portal hypertension or cancer progression.

CONCLUSIONS

We presented a rare case of NRH induced by T-DM1 in a patient with lung adenocarcinoma. A high index of suspicion for liver injury and NRH must be maintained for patients who develop liver test abnormalities and/or signs of portal hypertension during treatment with T-DM1. This is the first report of a successful dose reduction in a patient with NRH induced by T-DM1, suggesting that it is possible to maintain the drug while it is being effective for lung cancer treatment.

Liver Stiffness by Transient Elastography Correlates With Degree of Portal Hypertension in Common Variable Immunodeficiency Patients With Nodular Regenerative Hyperplasia

Nodular regenerative hyperplasia (NRH) is associated with high morbidity and mortality in patients with common variable immunodeficiency (CVID). While liver biopsy is the gold standard for NRH diagnosis, a non-invasive technique could facilitate early disease recognition, monitoring, and/or immune intervention. We performed a cross-sectional analysis of ultrasound-based transient elastography (TE) in patients with CVID to evaluate liver stiffness and compared this between patients with (N = 12) and without (N = 6) biopsy-proven NRH. Additionally, these data were compared to a cohort followed at our institution for non-alcoholic fatty liver disease (NAFLD) (N = 527), a disease for which TE has routine diagnostic use. Clinical and pathologic features of NRH were evaluated as correlates of liver stiffness, and receiver operating characteristic curves were used to define a liver stiffness cutoff with diagnostic utility for NRH among CVID patients. CVID patients with NRH had a more severe disease presentation compared to those without. This included increased autoinflammatory disease comorbidities, combined B-cell and T-cell dysfunction, and abnormal liver biochemistries (specifically an increased mean alkaline phosphatase level [proximal to TE, 250 vs. 100 U/L; p = 0.03; peak, 314 vs. 114 U/L; p = 0.02). Results of TE demonstrated a significantly elevated liver stiffness in CVID patients with NRH (mean 13.2 ± 6.2 kPa) as compared to both CVID patients without NRH (mean 4.6 ± 0.9 kPa) and non-CVID patients with NAFLD (mean 6.9 ± 5.5 kPa) (p < 0.01). No single or composite histopathologic feature of NRH correlated with liver stiffness including nodule size, nodule density, sinusoidal dilation, fibrosis, and/or lymphocytosis. In contrast, liver stiffness by TE was significantly correlated with clinical parameters of portal hypertension, including an elevated hepatic venous pressure gradient, an increased splenic longitudinal diameter, presence of varices, and presence of peripheral edema. A liver stiffness of greater than or equal to 6.2 kPa was a clinically significant cutoff for NRH in CVID patients. We propose that TE has diagnostic utility in CVID, particularly in the presence of immunophenotypic features such as combined B-cell and T-cell dysfunction, autoinflammatory comorbidities, and/or abnormal liver tests. Elevated liver stiffness by TE should raise suspicion for NRH in patients with CVID and prompt expedited evaluation by hepatology.

Nodular regenerative hyperplasia in X-linked agammaglobulinemia: An underestimated and severe complication

BACKGROUND

Late-onset complications in X-linked agammaglobulinemia (XLA) are increasingly recognized. Nodular regenerative hyperplasia (NRH) has been reported in primary immunodeficiency but data in XLA are limited.

OBJECTIVES

This study sought to describe NRH prevalence, associated features, and impact in patients with XLA.

METHODS

Medical records of all patients with XLA referred to the National Institutes of Health between October 1994 and June 2019 were reviewed. Liver biopsies were performed when clinically indicated. Patients were stratified into NRH+ or NRH- groups, according to their NRH biopsy status. Fisher exact test and Mann-Whitney test were used for statistical comparisons.

RESULTS

Records of 21 patients with XLA were reviewed, with a cumulative follow-up of 129 patient-years. Eight patients underwent ≥1 liver biopsy of whom 6 (29% of the National Institutes of Health XLA cohort) were NRH+. The median age at NRH diagnosis was 20 years (range, 17-31). Among patients who had liver biopsies, alkaline phosphatase levels were only increased in patients who were NRH+ (P = .04). Persistently low platelet count (<100,000 per μL for >6 months), mildly to highly elevated hepatic venous pressure gradient and either hepatomegaly and/or splenomegaly were present in all patients who were NRH+. In opposition, persistently low platelet counts were not seen in patients who were NRH-, and hepatosplenomegaly was observed in only 1 patient who was NRH-. Hepatic venous pressure gradient was normal in the only patient tested who was NRH-. All-cause mortality was higher among patients who were NRH+ (5 of 6, 83%) than in the rest of the cohort (1 of 15, 7% among patients who were NRH- and who were classified as unknown; P = .002).

CONCLUSIONS

NRH is an underreported, frequent, and severe complication in XLA, which is associated with increased morbidity and mortality.

Antiphospholipid syndrome with mesenteric vein thrombosis and hepatic nodular regenerative hyperplasia in a child: A case report

RATIONALE

Hepatic nodular regenerative hyperplasia (NRH), a nonspecific change in the liver parenchyma, is very rare in children. Hepatic microvascular changes may be the cause, as these vascular changes are uncommon in children. Antiphospholipid syndrome (APS), an autoimmune disease characterized by vascular thromboembolism, is extremely unusual in children.

PATIENT CONCERNS

A 13-year-old girl who presented with abdominal pain and elevated liver enzymes was transferred to our hospital. Abdominal computed tomography and magnetic resonance imaging showed a massive mesenteric venous thrombus and a malignant mass with liver metastasis.

DIAGNOSES

Her immunological profile was positive for antinuclear antibodies (ANA) at a titer of 1/160 (nucleolar pattern), anticardiolipin antibodies (aCL) immunoglobulin G, and anti-histone antibody. A liver biopsy revealed hepatic NRH.

INTERVENTIONS

The patient was initially started on heparin upon hospitalization and switched to warfarin and a vitamin K antagonist and continued treatment with international normalized ratio monitoring.

OUTCOMES

Her symptoms improved after 9 months of anticoagulation therapy.

LESSONS

In the presence of hepatic NRH or vascular thrombosis in children, we recommend that APS be differentially diagnosed using lupus anticoagulant and aCL and appropriate management be implemented.

Liver tumors in children with chronic liver diseases

Liver tumors are rare in children, but the incidence may increase in some circumstances and particularly in chronic liver diseases. Most liver tumors consequent to chronic liver diseases are malignant hepatocellular carcinoma. Other liver tumors include hepatoblastoma, focal nodular hyperplasia, adenoma, pseudotumor, and nodular regenerative hyperplasia. Screening of suspected cases is beneficial. Imaging and surrogate markers of alpha-fetoprotein are used initially as noninvasive tools for surveillance. However, liver biopsy for histopathology evaluation might be necessary for patients with inconclusive findings. Once the malignant liver tumor is detected in children with cirrhosis, liver transplantation is currently considered the preferred option and achieves favorable outcomes. Based on the current evidence, this review focuses on liver tumors with underlying chronic liver disease, their epidemiology, pathogenesis, early recognition, and effective management.

Marked Increase of Gamma-Glutamyltransferase as an Indicator of Drug-Induced Liver Injury in Patients without Conventional Diagnostic Criteria of Acute Liver Injury

<b><i>Introduction:</i></b> Clinically significant drug-induced liver injury (DILI) is defined by elevations of alanine aminotransferase (ALT) ≥5 times the upper limit of normal (ULN), alkaline phosphatase (ALP) ≥2 × ULN, or ALT ≥3 × ULN and total bilirubin TBIL &#x3e;2 × ULN. However, DILI might also occur in patients who do not reach those thresholds and still may benefit from discontinuation of medication. <b><i>Methods:</i></b> Fifteen patients recruited for our prospective study on potentially hepatotoxic drugs were included. DILI diagnosis was based on RUCAM (Roussel Uclaf Causality Assessment Method) score and expert opinion and was supported by an in vitro test using monocyte-derived hepatocyte-like (MH) cells. <b><i>Results:</i></b> Median RUCAM score was 6 (range 4–8), indicating that DILI was possible or probable in all cases. The predominant types of liver injury were mixed (60%) and cholestatic (40%). While no elevation above 2 × ULN of ALP and TBIL was observed, gamma-glutamyltransferase (GGT) above 2 × ULN was identified in 8 of the patients. Six of the 15 patients did not achieve full remission and showed persistent elevation of GGT, which was significantly associated with peak GGT elevation above 2 × ULN (<i>p</i> = 0.005). <b><i>Conclusion:</i></b> Here we present a case series of patients with liver enzyme elevation below the conventional thresholds who developed DILI with a predominant GGT elevation leading to drug withdrawal and/or chronic elevation of liver parameters, in particular of GGT. Thus, we propose that DILI should be considered in particular in cases with marked increase of GGT even if conventional DILI threshold levels are not reached, resulting in discontinuation of the causative drug and/or close monitoring of the patients.

Mild changes of hepatic nodular regenerative hyperplasia may cause portal hypertension and be visible on reticulin but not hematoxylin and eosin staining

Nodular regenerative hyperplasia (NRH) can manifest as alternating parenchymal compression/expansion on hematoxylin and eosin (H&E) staining and as reticulin collapse/nodularity on reticulin staining. Histologic diagnosis can be challenging, especially when there is mild disease and on limited biopsy samples. We reviewed clinical and histologic parameters in a large series of NRH. We identified 60 liver specimens convincingly showing changes of NRH and reviewed them for clinical (age, sex, symptoms, lab values, portal hypertension [PHTN], NRH etiology) and histologic (inflammation, sinusoidal dilation, cholestasis, architectural change, portal vascular abnormalities, degree of changes on reticulin) parameters. The cases came from 28 women and 32 men (median age: 54 years). Most (55, 92%) were biopsies. Thirty patients were symptomatic. Forty-five cases showed mild NRH changes on reticulin; 24 of these (53%) showed them on H&E as well. Fifteen demonstrated well-developed changes on reticulin, which were always seen on H&E as well. Sinusoidal dilation was commonly observed in both of these subgroups (88% overall). Portal vascular abnormalities were seen in 33%. Well-developed NRH was diffuse more often than mild NRH (53% vs. 4%, P < 0.0001). Twenty-nine patients had clinically confirmed or likely PHTN. Of these, 21 showed mild and 8 showed well-developed NRH changes; only 3 had concomitant advanced fibrosis. Chemotherapy was the most frequent known cause of NRH; 30 patients lacked any definite etiology. NRH can be difficult to diagnose on biopsy, particularly since mild changes may be visible on reticulin but not H&E; even these patients can have PHTN. Additionally, NRH is often idiopathic, potentially lowering clinical and pathologic suspicion. Pathologists should have a low threshold for ordering reticulin stains, especially when a patient is known to have PHTN. Sinusoidal dilation, while nonspecific, commonly accompanies NRH.

Hepatocyte-specific contrast-enhanced MRI findings of focal nodular hyperplasia-like nodules in the liver following chemotherapy in pediatric cancer patients

PURPOSE

We aimed to assess the MRI findings and follow-up of multiple focal nodular hyperplasia (FNH)- like lesions in pediatric cancer patients diagnosed by imaging findings.

METHODS

We retrospectively analyzed clinical data and MRI examinations of 16 pediatric patients, who had been scanned using gadoxetate disodium (n=13) and gadobenate dimeglumine (n=3). Hepatic nodules were reviewed according to their number, size, contour, T1- and T2-weighted signal intensities, arterial, portal, delayed and hepatobiliary phase enhancement patterns. Follow-up images were evaluated for nodule size, number, and appearance.

RESULTS

All 16 patients received chemotherapy in due course. Time interval between the initial diagnosis of cancer and detection of the hepatic nodule was 2-14 years. Three patients had a single lesion, 13 patients had multiple nodules. The median size of the largest nodules was 19.5 mm (range, 8-41 mm). Among 16 patients that received hepatocyte-specific agents, FNH-like nodules appeared hyperintense in 11 and isointense in 5 on the hepatobiliary phase. During follow-up, increased number and size of the nodules were seen in 4 patients. The nodules showed growth between 6-15 mm.

CONCLUSION

Liver MRI using hepatocyte-specific agents is a significant imaging method for the diagnosis of FNH-like lesions, which can occur in a variety of diseases. Lesions can increase in size and number in pediatric patients.

A case of idiopathic portal hypertension accompanying multiple hepatic nodular regenerative hyperplasia in a patient with systemic sclerosis

Idiopathic portal hypertension (IPH) is one of the background diseases causing nodular regenerative hyperplasia (NRH). Furthermore, IPH patients accompanied with autoimmune diseases, such as systemic lupus erythematosus (SLE) and systemic sclerosis (SSc), are more likely to form NRH in the liver. A 76-year-old woman had been aware of the Raynaud's phenomenon and scleroderma for the past 30 years. In this case, she presented with abdominal fullness, and her imaging analysis revealed ascites and multiple liver nodules. On Gd-EOB-DTPA enhanced magnetic resonance imaging (EOB-MRI), donut-like uptake was observed in the nodules in the hepatobiliary phase. Liver biopsy of a nodule demonstrated that it was composed of hyperplastic hepatocytes without fibrous septa, and dilated sinusoids were observed beside the nodule. Conversely, background liver showed that peripheral portal veins appeared stenotic with dense fibrosis in the portal area. The final diagnosis was that multiple NRH of the liver developed in SSc patient accompanying IPH. This case suggests that NRH may be unexpectedly diagnosed in patients with autoimmune diseases accompanying IPH.

Nodular Regenerative Hyperplasia of the Liver in Rheumatic Disease: Cases and Review of the Literature

Nodular regenerative hyperplasia (NRH) is a rare disease that is characterized by benign transformation of the hepatic parenchyma into small nodules with little to no fibrosis. Nodular regenerative hyperplasia is a cause of noncirrhotic portal hypertension. Symptoms can range from asymptomatic disease to more serious complications of portal hypertension such as esophageal varices and ascites. Nodular regenerative hyperplasia has been described in association with a variety of different rheumatologic, hematologic, and oncologic diseases, as well as in immune deficiency states and with exposures to certain toxins. Diagnosis is made by histology, and the treatment involves addressing the underlying disease. The first description of this rare disease was actually described in a patient with rheumatoid arthritis, neutropenia, and splenomegaly (Felty's Syndrome). We describe 2 cases of NRH associated with underlying rheumatic disorders, in one of which NRH was actually the presenting feature of the patient's underlying autoimmune condition. Subsequently, we provide a brief review of the literature of NRH in autoimmune disease with respect to epidemiology, cause, clinical manifestations, diagnosis, and treatment.

Hepatopulmonary Syndrome in an Adolescent With Insidious Hypoxia and Small Intrahepatic Portal Venous Shunts: Posttransplant Benefit From Sildenafil

We report a patient without known preexisting liver disease who presented with hepatopulmonary syndrome (HPS) due to aberrant intrahepatic portal venous development leading to portosystemic shunting. Liver transplantation resulted in resolution of portal hypertension and HPS and sildenafil was safely tolerated in the treatment of persistent fatigue and hypoxemia. Twelve months later, patient has normal allograft function and has returned to normal activity.

Pulmonary Complications in Candidates for Liver Transplantation

The liver plays a pivotal role in maintaining the homeostasis of various organ systems. Also, end-stage liver disease and its complications are major causes of morbidity and mortality among adults. Individuals who develop a chronic liver disease are at increased risk of progression to multi-organ dysfunction, including the pulmonary system. The clinical complications of pulmonary problems related to the presence of liver disease range from mild (such as hypoxemia) to life-threatening diseases (such as portopulmonary hypertension and hepatopulmonary syndrome). Herein, the major pulmonary complications related to liver cirrhosis and considerations for performing liver transplantation are reviewed.

Drug induced liver injury: an update

Drug induced liver injury (DILI) is a relatively rare hepatic condition in response to the use of medications, illegal drugs, herbal products or dietary supplements. It occurs in susceptible individuals through a combination of genetic and environmental risk factors believed to modify drug metabolism and/or excretion leading to a cascade of cellular events, including oxidative stress formation, apoptosis/necrosis, haptenization, immune response activation and a failure to adapt. The resultant liver damage can present with an array of phenotypes, which mimic almost every other liver disorder, and varies in severity from asymptomatic elevation of liver tests to fulminant hepatic failure. Despite recent research efforts specific biomarkers are not still available for routine use in clinical practice, which makes the diagnosis of DILI uncertain and relying on a high degree of awareness of this condition and the exclusion of other causes of liver disease. Diagnostic scales such as the CIOMS/RUCAM can support the causality assessment of a DILI suspicion, but need refinement as some criteria are not evidence-based. Prospective collection of well-vetted DILI cases in established DILI registries has allowed the identification and validation of a number of clinical variables, and to predict a more severe DILI outcome. DILI is also in need of properly designed clinical trials to evaluate the efficacy of new DILI treatments as well as older drugs such as ursodeoxycholic acid traditionally used to ameliorate cholestasis or corticosteroids now widely tried in the oncology field to manage the emergent type of hepatotoxicity related to immune checkpoint inhibitors.

The Pathogenesis of Systemic Sclerosis: An Understanding Based on a Common Pathologic Cascade across Multiple Organs and Additional Organ-Specific Pathologies

Systemic sclerosis (SSc) is a multisystem autoimmune and vascular disease resulting in fibrosis of various organs with unknown etiology. Accumulating evidence suggests that a common pathologic cascade across multiple organs and additional organ-specific pathologies underpin SSc development. The common pathologic cascade starts with vascular injury due to autoimmune attacks and unknown environmental factors. After that, dysregulated angiogenesis and defective vasculogenesis promote vascular structural abnormalities, such as capillary loss and arteriolar stenosis, while aberrantly activated endothelial cells facilitate the infiltration of circulating immune cells into perivascular areas of various organs. Arteriolar stenosis directly causes pulmonary arterial hypertension, scleroderma renal crisis and digital ulcers. Chronic inflammation persistently activates interstitial fibroblasts, leading to the irreversible fibrosis of multiple organs. The common pathologic cascade interacts with a variety of modifying factors in each organ, such as keratinocytes and adipocytes in the skin, esophageal stratified squamous epithelia and myenteric nerve system in gastrointestinal tract, vasospasm of arterioles in the heart and kidney, and microaspiration of gastric content in the lung. To better understand SSc pathogenesis and develop new disease-modifying therapies, it is quite important to understand the complex pathogenesis of SSc from the two distinct perspectives, namely the common pathologic cascade and additional organ-specific pathologies.

Anti-programmed cell death-1 and anti-programmed cell death ligand-1 immune-related liver diseases: from clinical pivotal studies to real-life experience

INTRODUCTION

Monoclonal antibodies directed against programmed cell death-1 (anti-PD-1) and its ligand (anti-PD-L1) showed a significant efficacy among different immunogenic metastatic tumors such as melanoma, non-small cell lung cancer (NSCLC), renal cell carcinoma (RCC). Between immune-related adverse events (irAEs) dependent on immune checkpoint inhibitors (ICPIs), immune-related liver diseases are uncommon and a definitive diagnosis is not always feasible.

AREAS COVERED

We revised data from phase II/III clinical trials and real-world retrospective analyses on liver-related adverse events induced by anti-PD-1 (nivolumab/pembrolizumab) and anti-PD-L1 (atezolizumab) in advanced cancer populations (melanoma, NSCLC and RCC). Furthermore, we described clinical-pathological patterns of immune-related liver diseases in real-life.

EXPERT OPINION

Use of anti-PD-1 and anti-PD-L1 led to a paradigm shift in the management of patients with melanoma, NSCLC and RCC. IrAEs can occur potentially in any tissue, leading to discontinuation of ICPIs, at least in a small proportion of these patients, and to a negative impact on their prognosis. Hepatobiliary immune-related adverse events are underestimated due to inappropriate monitoring. Development of novel diagnostic and therapeutic strategies for cancer patients receiving ICPIs as well as the identification of predictive biomarkers of liver injury could allow a better patients' selection and improve clinical outcomes of immune-related liver diseases.

Hepatic manifestations in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a multi-organic autoimmune disease with a wide variety of clinical manifestations. However, hepatic dysfunction is not included in the diagnostic criteria for the disease and has not been recognized properly. The spectrum of hepatic involvement described in these patients ranges from abnormalities in liver function tests (LFTs) to fulminant hepatic failure. Usually, abnormalities in LFTs are only mild and transient, have a hepatocellular pattern and are not related to SLE but rather are mostly drug related. The most frequent finding on liver biopsy is steatosis (non-alcoholic fatty liver disease). Patients do not frequently progress to advanced chronic liver disease, and their outcome is favourable. Those who develop cirrhosis have traditional risk factors, such as other non-SLE-related conditions. In this work, we aim to review hepatic manifestations in patients with SLE, as well as the diagnostic and therapeutic approaches used for different liver diseases in these patients.

Aberrant von Willebrand factor expression of sinusoidal endothelial cells and quiescence of hepatic stellate cells in nodular regenerative hyperplasia and obliterative portal venopathy

AIMS

Nodular regenerative hyperplasia (NRH) and obliterative portal venopathy (OPV), entities that comprise idiopathic non-cirrhotic portal hypertension (INCPH), are under-recognised diseases of uncertain aetiology and the diagnosis can be easily missed on liver biopsy. The expression of CD34 and von Willebrand factor (vWF) in liver sinusoidal endothelial cells (LSEC) and alpha-smooth muscle actin (ASMA) in hepatic stellate cells (HSCs) is unknown in NRH and OPV. We sought to investigate the pathogenesis and potential immunomarkers that might aid in making the diagnosis of NRH and OPV.

METHODS AND RESULTS

Immunohistochemical (IHC) staining for CD34, vWF and ASMA was performed in clinically and histologically well-characterised NRH (n = 15) and OPV (n = 47) liver specimens. Among the 47 OPV cases, 37 (78.7%) had concurrent features of NRH. CD34 positive staining was mainly confined to small vessels in the portal tracts and LSECs in periportal areas, a finding similar to that in non-NRH/OPV livers. However, expression of vWF in LSECs was positive in the compressed sinusoids of NRH and in a patchy or geographic pattern, particularly prominent in the perivenular areas and dilated sinusoids of OPV cases. HSCs were negative for ASMA in all NRH and OPV cases.

CONCLUSION

Our findings indicate that NRH may be a subtle but common concurrent morphological feature in OPV. The aberrant expression of vWF in LSECs suggests that endothelial injury may play a role in the pathogenesis, which may thus aid in the recognition and diagnosis of NRH and OPV, particularly when confronted with otherwise apparent normal liver histology on needle biopsy.

Vascular Anomalies of the Pediatric Liver

The liver is a unique organ as it receives afferent blood supply from the umbilical vein, portal vein, and hepatic artery in the developing embryo but has only one efferent drainage method, through the hepatic veins. In the postnatal period, about 70% of the afferent blood flow into the liver is from the portal venous system, unique vessels that begin and end in a capillary system. Vascular anomalies of the hepatic artery, hepatic veins, portal vein, and/or umbilical vein can be congenital or acquired secondary to inflammation and/or infection, trauma, systemic disorders, or iatrogenic causes. The vascular anomalies can be incidental findings at imaging, or the infant or child can present with symptoms such as abdominal pain and ascites, be diagnosed with gastrointestinal bleeding, and have abnormal liver function test results. Imaging can demonstrate vascular findings such as shunts, thrombosis, or collaterals; secondary parenchymal findings such as diffuse or focal abnormal enhancement patterns; and parenchymal lesions such as regenerative nodules. This article discusses and illustrates vascular disorders of the liver that may be encountered in the pediatric population. These include (a) normal vascular variants; (b) congenital anomalies (preduodenal portal vein and infradiaphragmatic total anomalous pulmonary venous return); (c) acquired thromboses (extrahepatic portal venous thrombosis); (d) inflammatory vascular conditions, which can result in hepatic artery aneurysms or pseudoaneurysms; (e) hepatic venous outflow disorders (veno-occlusive disease); and shunt lesions. Liver transplantation and associated vascular complications are a large topic and will not be reviewed in this article. Knowledge of the vascular and parenchymal changes seen with these entities can aid imaging diagnosis and guide appropriate management. ^©RSNA, 2019.

Safety of trastuzumab after trastuzumab emtansine-induced nodular regenerative hyperplasia: A case report

INTRODUCTION

Trastuzumab emtansine is an antibody-drug conjugate targeting the human epidermal growth factor receptor 2 use in recurrent metastatic breast cancer. Cases of trastuzumab emtansine-induced nodular regenerative hyperplasia are often reported as overt noncirrhotic portal hypertension with ascites and variceal bleeding.

CASE REPORT

We report the case of a 61-year-old woman who present multiple stellate angiomas with gradual increased liver transaminases and reduced platelet count during a 27-months course on trastuzumab emtansine therapy for recurrent metastatic breast cancer. After the nodular regenerative hyperplasia was histologically confirmed, the trastuzumab emtansine was stopped. After two months, trastuzumab was restarted together with exemestane. During trastuzumab therapy, the patient had a normalization of liver transaminases, platelet count and a gradual improvement of her stellate angiomas. Trastuzumab was continued for 15 months without any reoccurrence of nodular regenerative hyperplasia.

MANAGEMENT AND OUTCOME

Nodular regenerative hyperplasia should be suspected after one year of trastuzumab emtansine treatment in patients with signs of portal hypertension without cirrhosis. Definitive cessation of trastuzumab emtansine is required after a diagnosis of nodular regenerative hyperplasia and complete resolution of symptoms generally takes several months.

DISCUSSION

Based on fundamental studies, nodular regenerative hyperplasia is probably caused by the emtansine (DM1) part of the trastuzumab emtansine. It is still unclear if trastuzumab therapy can be reintroduced after nodular regenerative hyperplasia induced by trastuzumab emtansine, depriving the patient of a HER2-targeted therapy. Only one case reported having given trastuzumab in this situation over one month. In our case, trastuzumab was reintroduced without any complications for a long extent following TDM1-associated nodular regenerative hyperplasia.

Heterogeneity of Liver Disease in Common Variable Immunodeficiency Disorders

Common variable immunodeficiency (CVID) is the most frequent primary immunodeficiency (PID) in adulthood and is characterized by severe reduction of immunoglobulin serum levels and impaired antibody production in response to vaccines and pathogens. Beyond the susceptibility to infections, CVID encompasses a wide spectrum of clinical manifestations related to a complex immune dysregulation that also affects liver. Although about 50% CVID patients present persistently deranged liver function, burden, and nature of liver involvement have not been systematically investigated in most cohort studies published in the last decades. Therefore, the prevalence of liver disease in CVID widely varies depending on the study design and the sampling criteria. This review seeks to summarize the evidence about the most relevant causes of liver involvement in CVID, including nodular regenerative hyperplasia (NRH), infections and malignancies. We also describe the clinical features of liver disease in some monogenic forms of PID included in the clinical spectrum of CVID as ICOS, NFKB1, NFKB2, CTLA-4, PI3Kδ pathway, ADA2, and IL21-R genetic defects. Finally, we discuss the clinical applications of the various diagnostic tools and the possible therapeutic approaches for the management of liver involvement in the context of CVID.

Nodular regenerative hyperplasia - An under-recognized vascular disorder of liver

INTRODUCTION

Nodular regenerative hyperplasia (NRH) is a rare hepatic vascular disorder which is often associated with wide variety of systemic diseases. Intrahepatic microvascular injury and subsequent altered perfusion state leads to development of non-cirrhotic portal hypertension in many of these patients. Diagnosis of NRH often remains unsuspected clinically and liver biopsy is essential for the diagnosis and exclusion of fibrosis. We herein, present clinicopathological features of 22 NRH cases. In addition we assessed CK7 and CD34 expression in hepatocytes and sinusoidal endothelial cells respectively.

RESULTS

Most of the cases were associated with systemic disorders, predominantly immunological, inflammatory and drug-related injuries. Signs and symptoms of portal hypertension were found in 86.4 % patients. Majority of the patients showed a predominant mild cholestatic pattern of liver function tests. Nearly all the (21/22) cases showed CK7 positivity in centrizonal hepatocytes which ranged from <10 % cells to diffuse perivenular positivity extending into the midzonal areas. CD34 positivity in sinusoidal endothelial cells was seen in all the cases, which was prominent in periportal areas in all cases; while perivenular (n = 20) and midzonal (n = 14) areas also showed CD34 positive sinusoidal endothelial cells.

CONCLUSION

This study highlights the role of pathologist in the diagnosis of NRH and stresses upon the need for awareness of NRH as a cause of unexplained portal hypertension in patients with underlying systemic diseases. The altered perfusion state in NRH leads to phenotypic shift in centrizonal atrophic hepatocytes and sinusoidal endothelial cells (as depicted by IHC) which may be responsible for development of portal hypertension.

Diagnostic and prognostic assessment of suspected drug-induced liver injury in clinical practice

Idiosyncratic drug-induced liver injury (DILI) is a challenging liver disorder because it can present with a range of phenotypes, mimicking almost every other hepatic disease, and lacks specific biomarkers for its diagnosis. Hence, a confident DILI diagnosis is seldom possible as it relies on the precise establishment of a temporal sequence between the exposure to a given prescription drug or sometimes hidden herbal product/over the counter medication as well as the exclusion of other aetiologies of liver disease. However, an accurate diagnosis is of most importance, as prompt withdrawal of the causative agent is essential in DILI management. Indeed, DILI can be severe and even fatal or in a fraction of cases evolve to chronic damage, but specific biomarkers for predicting mortality/liver transplantation or a chronic outcome in the very early phases of DILI are not yet available. In this article, we discuss the best diagnostic and prognostic approach of a DILI suspicion by judiciously choosing and interpreting the standard tests currently used in clinical practice.

Noncirrhotic Portal Hypertension Secondary to Nodular Regenerative Hyperplasia Postrenal Transplant

Noncirrhotic portal hypertension (NCPH) is a well-known clinical entity, but often underdiagnosed. One of the common causes of NCPH is nodular regenerative hyperplasia (NRH) that presents as nodularity with features of portal hypertension and thus often diagnosed as cirrhosis. Although NRH has no histologic fibrosis, the liver synthetic function remains intact; thus, clinical diagnosis is essential because management may differ from cirrhosis. We were asked to consult in this series of 4 patients who had new-onset ascites after kidney transplantation and were diagnosed with NCPH from NRH.

Budd-Chiari Syndrome in a Patient With Simultaneous Diagnosis of Hepatic Sarcoidosis and Nodular Regenerative Hyperplasia

Budd-Chiari syndrome (BCS) is a rare vascular disorder characterized by an obstruction of the hepatic venous outflow. Nodular regenerative hyperplasia (NRH) may develop as a result of an underlying autoimmune disease such as hepatic sarcoidosis. Only a few case reports have described cases with either NRH or hepatic sarcoidosis associated with BCS. We present a 42-year-old man presenting with BCS and signs of portal hypertension who was found to have an underlying pathological diagnosis of both hepatic sarcoidosis and NRH and who was successfully treated with a transjugular intrahepatic portosystemic shunt.

Nodular Regenerative Hyperplasia: Expression Pattern of Glutamine Synthetase and a Potential Role for Hepatic Progenitor Cells

Nodular regenerative hyperplasia (NRH) is one of the most frequent causes of noncirrhotic intrahepatic hypertension, but is a difficult histologic diagnosis. The expression of glutamine synthetase (GS) and cytokeratin 7 (CK7) has been reported to be increased in other regenerative/vascular conditions, while CK7 and BerEP4 are also markers of hepatic progenitor cells. The aims of this study were to investigate the use of GS, CK7, and BerEP4 as the potential markers for NRH. This is a retrospective case series of NRH at Centre Hospitalier de l'Universite de Montreal between 1993 and 2013. Normal liver from partial hepatectomies for tumors were used as controls. GS, CK7, CK19, and BerEP4 immunohistochemical stains were performed on all specimens. Immunohistochemical staining patterns were scored from 0 to 3+. NRH was identified in 46 samples obtained from 26 patients. Liver chemistry profile was cholestatic in 45% of the patients. In 93% of the NRH cases, there was abnormal zone 2 expression of GS. Weak panacinar GS staining was seen in all the NRH cases. Aberrant CK7 expression was present in all cases of NRH, but were not associated with cholestasis. BerEP4 was overexpressed in 47% of the NRH cases (P<0.05); all cases with diffuse BerEP4 staining also showed extensive CK7 expression (P<0.01). NRH showed increased immunohistochemical GS staining that may support its morphologic diagnosis. Our findings suggest that there is an activation of hepatic progenitor cells in NRH.

Limited relevance and progression of histological alterations in the liver during thioguanine therapy in inflammatory bowel disease patients

Background: Thioguanine is associated with liver toxicity, especially nodular regenerative hyperplasia (NRH). We assessed if liver histology alters during long-term maintenance treatment with thioguanine in patients with inflammatory bowel disease (IBD). Methods: Liver specimens of thioguanine treated IBD patients with at least two liver biopsies were revised by two independent liver pathologists, blinded to clinical characteristics. Alterations in histopathological findings between first and sequential liver specimen were evaluated and associated clinical data, including laboratory parameters and abdominal imaging reports, were collected. Results: Twenty-five IBD patients underwent sequential liver biopsies prior to, at time of, or after cessation of thioguanine treatment. The median time between the first and second biopsy was 25 months (range: 14-54). Except for one normal liver specimen, any degree of irregularities including inflammation, steatosis, fibrosis and some vascular disturbances were observed in the biopsies. The rates of perisinusoidal fibrosis (91%), sinusoidal dilatation (68%) and nodularity (18%) were the same in the first and second liver biopsies. A trend towards statistical significance was observed for phlebosclerosis (36% of the first vs. 68% of the second biopsies, p = .092). Presence of histopathological liver abnormalities was not associated with clinical outcomes. Furthermore, two patients in this cohort had portal hypertension in presence of phlebosclerosis. In another two patients, nodularity of the liver resolved upon thioguanine withdrawal. Conclusion: Vascular abnormalities of the liver were commonly observed in thioguanine treated IBD patients, although these were not progressive and remained of limited clinical relevance over time.

EASL Clinical Practice Guidelines: Drug-induced liver injury

Idiosyncratic (unpredictable) drug-induced liver injury is one of the most challenging liver disorders faced by hepatologists, because of the myriad of drugs used in clinical practice, available herbs and dietary supplements with hepatotoxic potential, the ability of the condition to present with a variety of clinical and pathological phenotypes and the current absence of specific biomarkers. This makes the diagnosis of drug-induced liver injury an uncertain process, requiring a high degree of awareness of the condition and the careful exclusion of alternative aetiologies of liver disease. Idiosyncratic hepatotoxicity can be severe, leading to a particularly serious variety of acute liver failure for which no effective therapy has yet been developed. These Clinical Practice Guidelines summarize the available evidence on risk factors, diagnosis, management and risk minimization strategies for drug-induced liver jury.

Hepatotoxicity during 6-thioguanine treatment in inflammatory bowel disease and childhood acute lymphoblastic leukaemia: A systematic review

Background

The recently established association between higher levels of DNA-incorporated thioguanine nucleotides and lower relapse risk in childhood acute lymphoblastic leukaemia (ALL) calls for reassessment of prolonged 6-thioguanine (6TG) treatment, while avoiding the risk of hepatotoxicity.

Objectives

To assess the incidence of hepatotoxicity in patients treated with 6TG, and to explore if a safe dose of continuous 6TG can be established.

Data sources

Databases, conference proceedings, and reference lists of included studies were systematically searched for 6TG and synonyms from 1998–2018.

Methods

We included studies of patients with ALL or inflammatory bowel disorder (IBD) treated with 6TG, excluding studies with 6TG as part of an intensive chemotherapy regimen. We uploaded a protocol to PROSPERO (registration number CRD42018089424). Database and manual searches yielded 1823 unique records. Of these, 395 full-texts were screened for eligibility. Finally, 134 reports representing 42 studies were included.

Results and conclusions

We included data from 42 studies of ALL and IBD patients; four randomised controlled trials (RCTs) including 3,993 patients, 20 observational studies including 796 patients, and 18 case reports including 60 patients. Hepatotoxicity in the form of sinusoidal obstruction syndrome (SOS) occurred in 9–25% of the ALL patients in two of the four included RCTs using 6TG doses of 40–60 mg/m²/day, and long-term hepatotoxicity in the form of nodular regenerative hyperplasia (NRH) was reported in 2.5%. In IBD patients treated with 6TG doses of approximately 23 mg/m²/day, NRH occurred in 14% of patients. At a 6TG dose of approximately 12 mg/m²/day, NRH was reported in 6% of IBD patients, which is similar to the background incidence. According to this review, doses at or below 12 mg/m²/day are rarely associated with notable hepatotoxicity and can probably be considered safe.