Idiopathic Noncirrhotic Portal Hypertension: An Appraisal

Porto-sinusoidal Vascular Disease: Classification and Clinical Relevance

Non-cirrhotic portal hypertension (NCPH) is a well-recognized clinico-pathological entity, which is associated with clinical signs and symptoms, imaging, and endoscopic features of portal hypertension (PHT), in absence of cirrhosis. In patients with NCPH without known risk factors of PHT or extrahepatic portal vein thrombosis, the condition is called idiopathic non-cirrhotic portal hypertension (INCPH). There are multiple infectious, immune related causes, systemic diseases, drug and toxin exposures, haematological disorders, and metabolic risk factors that have been associated with this INCPH. However, the causal pathogenesis is still unclear. The Vascular liver disorders interest group group recently proposed porto-sinusoidal vascular disease (PSVD) as a syndromic entity, which provides definite histopathological criteria for diagnosis of NCPH (table 1). The three classical histo-morphological lesions specific for PSVD include obliterative portal venopathy, nodular regenerative hyperplasia, and incomplete septal fibrosis. The PSVD definition includes patients with portal vein thrombosis, PVT, and even those without PHT, thus broadening the scope of diagnosis to include patients who may have presented early, prior to haemodynamic changes consistent with PHT. However, this new diagnosis has pros and cons. The cons include mandating invasive liver biopsy to assess the PSVD histological triad in all patients with NCPH, an erstwhile clinical diagnosis in Asian patients. In addition, the natural history of the subclinical forms of PSVD without PHT and linear progression to develop PHT is unknown yet. In this review, we discuss the diagnosis and treatment of INCPH/PSVD, fallacies and strengths of the old and new schema, pathobiology of this disease, and clinical correlates in an Asian context. Although formulation of standardised diagnostic criteria is useful for comparison of clinical cohorts with INCPH/PSVD, prospective clinical validation in global cohorts is necessary to avoid misclassification of vascular disorders of the liver.

Evaluation of the histologic and immunohistochemical (CD34, glutamine synthetase) findings in idiopathic non-cirrhotic portal hypertension (INCPH)

AIM

Idiopathic non-cirrhotic portal hypertension (INCPH) is a vascular disorder of uncertain origin. Diagnosis can be challenging on liver biopsy. Despite diverse histomorphologic findings documented in literature, studies on the frequency of these findings are lacking. This study aims to assess both the histomorphologic features and the immunoexpression patterns of CD34 and glutamine synthetase (GS) in liver biopsies and searched for their contribution to the pathologic diagnosis of INCPH.

MATERIALS AND METHODS

Hematoxylin-eosin, CD34, and GS-stained liver needle biopsy sections of 16 patients clinically diagnosed with INCPH were retrospectively analyzed. Histologic findings such as portal vein narrowing, obliteration, or loss were grouped as major findings, while portal vein herniation, hypervascularized portal tracts, and periportal abnormal vessels were grouped as minor findings, and their frequency were evaluated. Periportal endothelial CD34 stained areas were measured via ocular micrometer. The distribution of GS immunoexpression was evaluated. Eighteen healthy liver donor biopsies were evaluated as controls.

RESULTS

In INCPH cases, 58% of portal tracts showed major findings, compared to 15% in the control group (p < 0.001). Minor findings were observed in 16% of INCPH cases and 7% of controls (p = 0.014). The number of portal tracts with histologic findings is significantly higher in INCPH than in control liver biopsies. Abnormal portal tract distribution, like being close to each other, was seen in 75% of INCPH cases but not in controls (p < 0.001). Nodular regenerative hyperplasia (NRH) was present in 31% of cases. Periportal CD34 expression was higher in INCPH, and affected areas were larger than in controls (p < 0.001). Irregular GS staining, i.e. GS staining with patchy distribution in zone 3, and/or periportal and zone 2 hepatocytes, was found in 62% of INCPH cases, while controls showed the usual pattern (p < 0.001).

CONCLUSION

In the biopsy diagnosis of INCPH, in addition to the presence of major histologic findings and the amount of portal tracts displaying these features, the expression of endothelial CD34 in periportal areas, and irregular hepatocellular GS expression can also be considered as supporting feature.

A Case of Non-cirrhotic Portal Hypertension With Antiphospholipid Syndrome

Nodular regenerative hyperplasia (NRH) and obliterative portal venopathy (OPV) are two causes of non-cirrhotic portal hypertension (NCPH), which is a vascular liver disease wherein clinical signs of portal hypertension (PHT), such as esophageal varices, ascites, and splenomegaly develop in the absence of cirrhosis and portal vein thrombosis. The etiology often remains unidentified, but herein we present the case of a 56-year-old male with NCPH and refractory ascites who underwent liver biopsy confirming NRH and OPV. Etiological workup revealed beta-2 glycoprotein-1 and anticardiolipin antibodies, concerning antiphospholipid syndrome (APS) despite no prior history of thrombosis. The patient underwent a transjugular intrahepatic portosystemic shunt (TIPS) procedure for his refractory ascites and was started on prophylactic anticoagulation owing to a concern for APS with clinical improvement in his ascites and shortness of breath. Pursuing TIPS earlier in the setting of refractory ascites, as well as offering anticoagulation therapy for patients with possible APS to prevent the development of potential thromboses, could be appropriate recommendations to prevent complications in the disease course. This case report highlights the need for further investigations on the etiologies, diagnosis pathways, and treatment options for NCPH.

A Unique Presentation of Familial Idiopathic Colonic Varices

Colonic varices typically occur in the setting of portal hypertension, and patients may present with rectal bleeding or occult anemia. Idiopathic colonic varices occur infrequently in the absence of cirrhosis and can involve the entire colon. We present a case of a 54-year-old Eastern European woman who had undergone diagnostic colonoscopy for newly diagnosed sigmoid adenocarcinoma and was incidentally found to have colonic varices with normal portal pressure gradients. Her 38-year-old daughter was found to have similar varices, raising concerns for hereditary etiology.

Interventional Management of Portal Hypertension in Cancer Patients

PURPOSE OF REVIEW

To provide an overview of the classifications and clinical hallmarks of common cancer-related conditions that contribute to the high incidence of portal hypertension in this population and provide an update on currently available interventional radiology therapeutic approaches.

RECENT FINDINGS

In the last few decades, there have been significant advancements in understanding the pathophysiology of portal hypertension. This knowledge has led to the development of safer and more effective minimally invasive approaches. The main objective is to provide alternatives to prevent life-threatening complications from clinically significant portal hypertension and to allow the continuation of cancer treatment interventions that would otherwise be stopped. Clinicians involved in cancer care should be aware of risk factors, associated complications, and management of portal hypertension in cancer patients. Interventional radiology offers minimally invasive alternatives that play a central role in improving clinical outcomes and survival of these patients, allowing the continuation of cancer treatments.

Bioinformatics Analysis of Common Genetic and Molecular Traits and Association of Portal Hypertension with Pulmonary Hypertension

Portal hypertension (PH) is an important cause of pulmonary arterial hypertension(PAH), but its mechanism is still unclear. We used genetic data analysis to explore the shared genes and molecular mechanisms of PH and PAH. We downloaded the PH and PAH data from the GEO database, and used the weighted gene coexpression network analysis method (WGCNA) to analyze the coexpression modules of idiopathic noncirrhotic portal hypertension (INCPH) and cirrhotic portal hypertension (CPH) and pulmonary hypertension, respectively. Enrichment analysis was performed on the common genes, and differential gene expressions (DEGs) were used for verification. The target genes of INCPH and PAH were obtained by string and cytoscape software, and the miRNAs of target genes were predicted by miRwalk, miRDB, and TargetScan and their biological functions were analyzed; finally, we used PanglaoDB to predict the expression of target genes in cells. In WGCNA, gene modules significantly related to PAH, CPH, and INCPH were identified, and enrichment function analysis showed that the common pathway of PAH and CPH were “P53 signaling pathway,” “synthesis of neutral lipids”; PAH and INCPH are “terminal,” “Maintenance Regulation of Granules,” and “Toxin Transport.” DEGs confirmed the results of WGCNA; the common miRNA functions of PAH and cirrhosis were enriched for “P53 signaling pathway,” “TGF-β signaling pathway,” “TNF signaling pathway,” and “fatty acid metabolism,” and the miRNAs-mRNAs network suggested that hsa-miR-22a-3p regulates MDM2 and hsa-miR-34a-5p regulates PRDX4; the target genes of PAH and INCPH are EIF5B, HSPA4, GNL3, RARS, UTP20, HNRNPA2B1, HSP90B1, METAP2, NARS, SACM1L, and their target miRNA function enrichment showed EIF5B, HNRNPA2B1, HSP90B1, METAP2, NARS, SACM1L, and HSPA4 are associated with telomeres and inflammation, panglaoDB showed that target genes are located in endothelial cells, smooth muscle cells, etc. In conclusion, the mechanism of pulmonary hypertension induced by portal hypertension may be related to telomere dysfunction and P53 overactivation, and lipid metabolism and intestinal inflammation are also involved in this process.

Porto-sinusoidal vascular disorder

It is well established that portal hypertension can occur in the absence of cirrhosis, as reported in patients with immune disorders, infections and thrombophilia. However, similar histological abnormalities primarily affecting the hepatic sinusoidal and (peri)portal vasculature have also been observed in patients without portal hypertension. Thus, the term porto-sinusoidal vascular disorder (PSVD) has recently been introduced to describe a group of vascular diseases of the liver featuring lesions encompassing the portal venules and sinusoids, irrespective of the presence/absence of portal hypertension. Liver biopsy is fundamental for PSVD diagnosis. Specific histology findings include nodular regenerative hyperplasia, obliterative portal venopathy/portal vein stenosis and incomplete septal fibrosis/cirrhosis. Since other conditions including alcohol-related and non-alcoholic fatty liver disease, or viral hepatitis, or the presence of portal vein thrombosis may occur in patients with PSVD, their relative contribution to liver damage should be carefully assessed. In addition to histology and clinical diagnostic criteria, imaging and non-invasive tests such as liver and spleen stiffness measurements could aid in the diagnostic workup. The introduction of PSVD as a novel clinical entity will facilitate collaborative studies and investigations into the underlying molecular pathomechanisms encompassed by this term.

Pathological and imaging features of idiopathic non-cirrhotic portal hypertension

Idiopathic non-cirrhotic portal hypertension (INCPH), a kind of portal sinus vascular disease with unknown etiology, is characterized by the presence of clinical signs and symptoms of portal hypertension (PH) in the absence of liver cirrhosis or known risk factors accountable for PH. It has an extremely high rate of initial misdiagnosis and underdiagnosis. Liver biopsy is the only way to make a definitive diagnosis. Non-invasive modalities, such as CT imaging, are becoming a hot topic of interest in recent years. This article summarizes the pathological and CT/MRI features of INCPH and the key points of differentiation from cirrhosis, to improve clinicians' understanding of INCPH and reduce the rate of initial misdiagnosis and missed diagnoses.

Clinical Course of Porto-Sinusoidal Vascular Disease Is Distinct From Idiopathic Noncirrhotic Portal Hypertension

BACKGROUND & AIMS

Porto-sinusoidal vascular disease (PSVD) was recently proposed as novel clinical entity characterized by typical histological changes with or without portal hypertension (PH) in the absence of cirrhosis. Thus, we aimed to describe clinical characteristics and the outcome of PSVD patients and to compare these to patients meeting traditional idiopathic non-cirrhotic portal hypertension (INCPH) criteria.

METHODS

Patients undergoing liver biopsy (baseline) ±hepatic venous pressure gradient (HVPG) measurement at the Vienna General Hospital between 2000-2019 were screened for PSVD and INCPH criteria.

RESULTS

91 patients were diagnosed with PSVD of which 28 (30.8%) also fulfilled INCPH criteria (INCPH+/PSVD+). Specific histological and specific clinical PH signs were found in 72 (79.1%) and 54 (59.3%) patients, respectively. INCPH+/PSVD+ showed higher Child-Pugh-scores (7±2 vs 6±1 points; P = .002) and a higher prevalence of decompensation (57.1% vs 28.6%; P = .009) than INCPH-/PSVD+ patients. Importantly, hepatic decompensation after three years (3Y) occurred in 11.2% of PSVD patients with specific clinical signs of PH, while no decompensation occurred in patients with only specific histological or with unspecific clinical/histological signs (P = .002). When categorizing by INCPH definition, 3Y decompensation was 13.4% in INCPH+/PSVD+ and 3.8% in INCPH-/PSVD+ (P = .120). While overall mortality was similar in INCPH+/PSVD+ (n = 6; 21.4%) and INCPH-/PSVD+ (n = 10; 15.9%) patients (P = .558), liver-related mortality tended to be higher in INCPH+/PSVD+ (6.9%) than in INCPH-/PSVD+ (0%; P = .078).

CONCLUSION

Novel PSVD criteria facilitate diagnosis. Compared to INCPH, clinical course of PSVD patients is more favorable. Importantly, specific signs of PH including varices and collaterals are associated with hepatic decompensation and mortality.

Idiopathic Non-Cirrhotic Portal Hypertension and Porto-Sinusoidal Vascular Disease: Review of Current Data

Idiopathic non-cirrhotic portal hypertension (INCPH) is a clinicopathologic disease entity characterized by the presence of clinical signs and symptoms of portal hypertension (PH) in the absence of liver cirrhosis or known risk factors accountable for PH. Multiple hematologic, immune-related, infectious, hereditary and metabolic risk factors have been associated with this disorder. Still, the exact etiopathogenesis is largely unknown. The recently proposed porto-sinusoidal vascular disease (PSVD) scheme broadens the spectrum of the disease by also including patients without clinical PH who are found to have similar histopathologic findings on core liver biopsies. Three histomorphologic lesions have been identified as specific for PSVD to include obliterative portal venopathy, nodular regenerative hyperplasia and incomplete septal cirrhosis/fibrosis. However, these findings are often subtle, under-recognized and subjective with low interobserver agreement among pathologists. Additionally, the natural history of the subclinical forms of the disease remains unexplored. The clinical course is more favorable compared to cirrhosis patients, especially in the absence of clinical PH or liver dysfunction. There are no universally accepted guidelines in regard to diagnosis and treatment of INCPH/PSVD. Hence, this review emphasizes the need to raise awareness of this entity by highlighting its complex pathophysiology and clinicopathologic associations. Lastly, formulation of standardized diagnostic criteria with clinical validation is necessary to avoid misclassifying vascular diseases of the liver and to develop and implement targeted therapeutic strategies.

Key histopathologic features in idiopathic noncirrhotic portal hypertension: an interobserver agreement study and proposal for diagnostic criteria

Histologic features of idiopathic noncirrhotic portal hypertension (INCPH), loosely termed as obliterative portal venopathy (OPV), are heterogenous, often subtle, and overlap with other entities. To this date, no consensus histopathologic diagnostic criteria have been established for INCPH. For these reasons, rendering a reproducible consensus histologic diagnosis of OPV on a liver biopsy may often be challenging even for experienced hepatopathologists. We report herein a two-phase interobserver agreement study on the diagnosis of OPV and assessed the relative value of histologic features in 104 liver biopsies in distinguishing between INCPH and non-INCPH with the goal to obtain a consensus on specific practical diagnostic criteria. Six hepatopathologists blinded to clinical information and original pathologic diagnosis reviewed internet-based case study sets with high-resolution whole-slide images. The initial interobserver agreement on OPV was expectedly low, but significantly improved (moderate agreement in most categories) upon adopting a consensus view recognizing portal vein sclerosis as the only strong independent histologic predictor for INCPH, and that contrary to the conventional view, aberrant portal/periportal vessels does not significantly contribute to the positive assignment of OPV status. We propose a three-tiered classification with diagnostic criteria to facilitate the histologic assignment of OPV status for the evaluation of INCPH. Furthermore, we have validated the performance of the proposed criteria either based on histology alone or coupled with clinicopathologic correlation. This classification may aid in practical histologic assessment of liver biopsies with or without portal hypertension and help to improve diagnostic consistency and accuracy.

Histological analyses of trucut liver biopsies from patients with noncirrhotic portal fibrosis and extra-hepatic portal vein obstruction

Background

Both noncirrhotic portal fibrosis (NCPF) and extrahepatic portal venous obstruction (EHPVO) are important causes of noncirrhotic portal hypertension (PH) in the Asian region. In this study, we analyzed the histopathological changes of liver needle-core biopsies from patients with NCPF and EHPVO.

Patients and Methods

The patients were diagnosed as per the Asia Pacific Association for the Study of Liver (APASL) criteria. Minimum adequacy criteria for liver core biopsies were defined, and finally, 69 liver biopsies from patients with NCPF and 100 liver biopsies from patients with EHPVO were analyzed. All histological parameters were predefined, and three experienced pathologists analyzed the biopsies after reaching consensus. Institute ethics committee clearance was taken.

Results

Although some histological features were overlapping, phlebosclerosis of intra-hepatic branches of the portal vein (PV), periportal aberrant vascular channels, remnant portal tracts, and hepatic fibrosis beyond the portal tracts without the formation of complete hepatic nodules (P < 0.001 for all) were common histological characteristics of NCPF on core-needle liver biopsies; while maintained lobular architecture, nonspecific dilatation of PV branches, absence of intra-hepatic PV phlebosclerosis, aberrant vascular channels, and significant fibrosis were characteristics of EHPVO.

Conclusions

Despite the considerable histological overlap between NCPF and EHPVO, careful histological evaluation, supplemented by clinical features, radiological and biochemical findings can help in making a conclusive diagnosis. Patients with NCPF and EHPVO with clinical jaundice show transaminitis, high serum alkaline phosphatase level, more variceal bleed, and histological evidences of nodular regenerative hyperplasia.

Interobserver study on histologic features of idiopathic non-cirrhotic portal hypertension

Background

Histologic features of idiopathic non-cirrhotic portal hypertension (INCPH) may overlap with those without INCPH. Recently, these features have been recognized as part of the larger spectrum of porto-sinusoidal vascular disease (PSVD). We assessed interobserver agreement on histologic features that are commonly associated with INCPH and studied whether a provision of relevant clinical history improves interobserver agreement.

Methods

The examined histologic features include lobular (such as anisocytosis, nodular regeneration, sinusoidal dilatation, increased parenchymal draining veins, and incomplete fibrous septa) and portal tract changes (such as paraportal shunting vessel(s), portal tract remnant, increased number of portal vessels, and obliterative portal venopathy). Thirty-four archived liver samples from patients with (group A) and without (group B) INCPH were retrieved. A total of 90 representative images of lobules (L) and portal tracts (P) were distributed among 9 liver pathologists blinded to true clinical history. Each pathologist answered multiple choice questions based on the absence (Q1) or presence (Q2) of clinical history of portal hypertension. Fleiss’ kappa coefficient analysis (unweighted) was performed to assess interobserver agreement on normal versus abnormal diagnosis, in L and P, based on Q1 and Q2.

Results

The kappa values regarding normal versus abnormal diagnosis were 0.24, 0.24, 0.18 and 0.18 for L-Q1, L-Q2, P-Q1, and P-Q2, respectively. With true clinical history provided, the kappa values were L- 0.32, P-0.17 for group A and L-0.12, P-0.14 for group B. Four pathologists changed their assessments based on the provided history. Interobserver agreement on the interpretation of L and P as normal versus abnormal was slight to fair regardless of provision of clinical history.

Conclusions

Our findings indicate that the histologic features of INCPH/PSVD are not limited to patients with portal hypertension and are subject to significant interobserver variation.

Supplementary information

The online version contains supplementary material available at 10.1186/s13000-020-01049-0.

Histologic Lesions of Porto-Sinusoidal Vascular Disease Following Phlebotomy in Hemochromatosis

Background

Phlebotomy induces regression of liver fibrosis in genetic hemochromatosis. We assessed the histologic changes in pre-phlebotomy and post-phlebotomy liver biopsies from patients with HFE mutation as a model to study regression of fibrosis. We aimed to show that phlebotomy-induced histologic lesions overlap with porto-sinusoidal vascular disease (PSVD, also known as idiopathic non-cirrhotic portal hypertension), histologically.

Methods

A total of 51 biopsies (22 pre-phlebotomy and 29 post-phlebotomy) were reviewed, and three variables were studied: iron index indicative of the amount of accumulated iron (range 0 to 18), the combined score of vascular changes reflecting the presence of histological lesions that are described in PSVD (range 0 to 9) and the high-grade shunt vessel by calculating the proportion of portal tracts with shunt vessels, with a cutoff of 50%. Two-tailed Student's t-test and Fisher's exact test were performed to compare the means of two variables and frequencies of the histologic lesions in two groups, respectively. A P-value < 0.05 was considered statistically significant.

Results

The iron index was higher in the pre-phlebotomy compared to post-phlebotomy group (P = 0.01). Compared to the pre-phlebotomy group, the combined score was higher in the post-phlebotomy group when the cases of advanced fibrosis were excluded (P = 0.023) and remained higher when patients with risk factors for PSVD were further excluded (P = 0.034). The high-grade shunt vessel tended to be more common in the post-phlebotomy group when advanced fibrosis was excluded; however, the statistical significance was marginal (P = 0.056).

Conclusions

Phlebotomy reduces hepatic iron load and induces histologic lesions of PSVD in patients with HFE mutation. Our data support a postulation that some of the histologic lesions of PSVD represent vascular remodeling following a regression of fibrosis and may not be reflective of risk factors or etiopathogenesis of PSVD. Regressed fibrosis and PSVD may not be reliably distinguished in a limited sample, therefore warranting cautious interpretation in the right clinical context.

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.

Systemic lupus erythematosus complicated by noncirrhotic portal hypertension: A case report and review of literature

A 48 year-old Chinese woman suffering from polyarthritis, irregular fever and trichomadesis was admitted to the hospital. A diagnosis of systemic lupus erythematosus (SLE) was made based on polyarthritis, pancytopenia, reduced complement 3, multiple positive autoantibodies, a positive Coomb’s test and protein in her urine. In addition, splenomegaly was detected during physical examination and confirmed by abdominal ultrasonography and magnetic resonance imaging, indicating that the patient had SLE and portal hypertension. Further negative investigations ruled out the possibility of cirrhosis. The patient was diagnosed with active SLE complicated by noncirrhotic portal hypertension (NCPH) without liver histopathology, due to the patient’s refusal for liver biopsy. Portal vein diameter and splenomegaly decreased following treatment with methylprednisolone, hydroxychloroquine and metoprolol tartrate. To date, SLE complicated by NCPH has rarely been reported, as it is under-recognized clinically as well as pathologically. Here we describe a case of SLE complicated by NCPH and review the literature for its characteristics, which may contribute to improving the recognition of NCPH and reducing missed and delayed diagnosis of this disorder.

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.

Prevalence of histological features of idiopathic noncirrhotic portal hypertension in general population: a retrospective study of incidental liver biopsies

BACKGROUND

Idiopathic noncirrhotic portal hypertension (INCPH) is associated with histologic changes secondary to obliterative portal venopathy without cirrhosis. We studied the prevalence of individual histological features of INCPH in liver biopsies obtained incidentally during unrelated elective procedures and in elective liver biopsies with the diagnosis of fatty liver disease.

METHODS

A total of 53 incidental liver biopsies obtained intraoperatively during unrelated elective procedures and an additional 28 elective biopsies with the diagnosis of fatty liver disease without portal hypertension and cirrhosis were studied. Various histologic features of INCPH were evaluated.

RESULTS

Shunt vessel (30%), phlebosclerosis (27%), increased number of portal vessels (19%) and incomplete septa (17%) were common in these liver biopsies after confounding factors such as co-existing fatty liver disease or fibrosis were excluded. At least one feature of INCPH was noted in 90% of the biopsies. Eight (10%) biopsies showed 5-6 features of INCPH. In total, 11 (14%) of 81 patients had risk factors associated with INCPH, including hypercoagulability, autoimmune disease, exposure to drugs, and infections. No patient had portal hypertension at the end of the follow-up.

CONCLUSION

The histologic features of INCPH are seen in incidental liver biopsies and fatty liver disease without portal hypertension. Ten percent of the biopsies show 5-6 features of INCPH without portal hypertension. Interpreting histologic features in the right clinical context is important for proper patient care.