Diagnosis and treatment of benign liver nodules: Brazilian Society of Hepatology (SBH) recommendations

Hepatic adenoma: evolution of a more individualized treatment approach

BACKGROUND

Hepatic adenomas (HAs) are benign, solid liver lesions, which carry a risk of hemorrhage and malignant transformation. This review article highlights the advances in the diagnosis and management of HAs.

METHODS

A comprehensive review was performed using MEDLINE/PubMed and Web of Science databases with a search period ending on September 30, 2023. Using PubMed, the terms "hepatocellular," "hepatic," and "adenoma" were searched.

RESULTS

HA has been classified into at least 8 subtypes based on molecular pathology, each exhibiting unique histopathologic features, clinical considerations, and risk of malignant transformation. The most common subtype is inflammatory HA, followed by hepatocyte nuclear factor 1α-inactivated HA, β-catenin exon 3-mutated HA (βex3-HA), β-catenin exon 7- or 8-mutated HA, sonic hedgehog HA, and unclassified HA. Magnetic resonance imaging is the best imaging method for diagnosis and can distinguish among HA subtypes based on fat and telangiectasia pathologic characteristics. The risk of malignant transformation varies among molecular subtypes, ranging from <1% to approximately 50%. Up to 42% of HAs present with spontaneous intratumoral hemorrhage and peritoneal hemorrhage. In general, only 15% to 20% of patients require surgery. HA larger than 5 cm are more likely to be complicated by bleeding and malignant transformation, regardless of subtype, and should generally be resected. In particular, βex3-HA carries a high risk of malignant transformation and can be considered a true precancerous lesion.

CONCLUSION

The management of HAs is based on a multidisciplinary approach. Clinical decision-making should integrate information on gender, tumor size, and HA subtyping. In the future, patients with HA will benefit from novel medical therapies tailored to the individual molecular subtypes.

Surgical indications for solid hepatic benign tumors: An updated literature review

Hepatic hemangioma, focal nodular hyperplasia, and hepatic adenoma are the most common benign solid liver tumors. However, their surgical indications have been the subject of debate. Minimally invasive liver resection reduces the cost of surgery and may lead to overtreatment of benign liver tumors. Recently, there has been a growing understanding of the etiology, pathogenesis, and natural history of these tumors. Great progress has also been made in imaging. The use of MRI and contrast agents has improved the accuracy of non-invasive diagnosis of these tumors, and especially in the identification of specific molecular subtypes of liver adenoma. These factors have resulted in alterations of surgical indications for these tumors. This article examines recent literature and it discusses the surgical indications for hepatic hemangioma, focal nodular hyperplasia, and hepatic adenoma while summarizing modifications in clinical management.

A nationwide assessment of hepatocellular adenoma resection: Indications and pathological discordance

Hepatocellular adenomas (HCAs) are benign liver tumors associated with bleeding or malignant transformation. Data on the indication for surgery are scarce. We analyzed indications and outcome of patients operated for HCAs < 50 mm compared to HCAs ≥ 50 mm. Changes in final postoperative diagnosis were assessed. We performed a retrospective study that included patients who underwent resection for (suspected) HCAs in the Netherlands from 2014 to 2019. Indication for resection was analyzed and stratified for small (<50 mm) and large (≥50 mm) tumors. Logistic regression analysis was performed on factors influencing change in tumor diagnosis. Out of 222 patients who underwent surgery, 44 (20%) patients had a tumor <50 mm. Median age was 46 (interquartile range [IQR], 33-56) years in patients with small tumors and 37 (IQR, 31-46) years in patients with large tumors ( p  = 0.016). Patients with small tumors were more frequently men (21% vs. 5%, p  = 0.002). Main indications for resection in patients with small tumors were suspicion of (pre)malignancy (55%), (previous) bleeding (14%), and male sex (11%). Patients with large tumors received operations because of tumor size >50 mm (52%), suspicion of (pre)malignancy (28%), and (previous) bleeding (5.1%). No difference was observed in HCA-subtype distribution between small and large tumors. Ninety-six (43%) patients had a postoperative change in diagnosis. Independent risk factors for change in diagnosis were tumor size <50 mm (adjusted odds ratio [aOR], 3.4; p  < 0.01), male sex (aOR, 3.7; p  = 0.03), and lack of hepatobiliary contrast-enhanced magnetic resonance imaging (CE-MRI) (aOR, 1.8; p  = 0.04). Resection for small (suspected) HCAs was mainly indicated by suspicion of (pre)malignancy, whereas for large (suspected) HCAs, tumor size was the most prevalent indication. Male sex, tumor size <50 mm, and lack of hepatobiliary CE-MRI were independent risk factors for postoperative change in tumor diagnosis.

Benign liver lesions 2022: Guideline for clinical practice of Associazione Italiana Studio del Fegato (AISF), Società Italiana di Radiologia Medica e Interventistica (SIRM), Società Italiana di Chirurgia (SIC), Società Italiana di Ultrasonologia in Medicina e Biologia (SIUMB), Associazione Italiana di Chirurgia Epatobilio-Pancreatica (AICEP), Società Italiana Trapianti d'Organo (SITO), Società Italiana di Anatomia Patologica e Citologia Diagnostica (SIAPEC-IAP) - Part II - Solid lesions

Benign liver lesions are increasingly diagnosed in daily clinical practice due to the growing use of imaging techniques for the study of the abdomen in patients who have non-specific symptoms and do not have an increased risk of hepatic malignancy. They include simple or parasitic hepatic cysts and solid benign tumors which differ widely in terms of prevalence, clinical relevance, symptoms and natural history and often lead to significant clinical problems relating to diagnosis and clinical management. Following the need to have updated guidelines on the management of benign focal liver lesions, the Scientific Societies mainly involved in their management have promoted the drafting of a new dedicated document. This document was drawn up according to the present Italian rules and methodologies necessary to produce clinical, diagnostic, and therapeutic guidelines based on evidence. Here we present the second part of the guideline, concerning the diagnosis and clinical management of hemangioma, focal nodular hyperplasia, and hepatocellular adenoma.

Benign liver lesions 2022: Guideline for clinical practice of Associazione Italiana Studio del Fegato (AISF), Società Italiana di Radiologia Medica e Interventistica (SIRM), Società Italiana di Chirurgia (SIC), Società Italiana di Ultrasonologia in Medicina e Biologia (SIUMB), Associazione Italiana di Chirurgia Epatobilio-Pancreatica (AICEP), Società Italiana Trapianti d'Organo (SITO), Società Italiana di Anatomia Patologica e Citologia Diagnostica (SIAPEC-IAP) - Part I - Cystic lesions

Benign liver lesions are increasingly diagnosed in daily clinical practice due to the growing use of imaging techniques for the study of the abdomen in patients who have non-specific symptoms and do not have an increased risk of hepatic malignancy. They include simple or parasitic cysts and solid benign tumors which differ widely in terms of prevalence, clinical relevance, symptoms and natural history and often lead to significant clinical problems relating to diagnosis and clinical management. Following the need to have updated guidelines on the management of benign focal liver lesions, the Scientific Societies mainly involved in their management have promoted the drafting of a new dedicated document. This document was drawn up according to the present Italian rules and methodologies necessary to produce clinical, diagnostic, and therapeutic guidelines based on evidence. Here we present the first part of the guideline, concerning the characterization of focal hepatic lesions detected by ultrasound, and the diagnosis and clinical management of simple and parasitic hepatic cysts, and of polycystic liver disease.

Incidental Liver Lesions in children: A practical and evidence-based approach

Incidental liver lesions are increasingly being discovered in the context of the increased use of ultrasound studies and the majority are benign. In children, although individually rare, the differential diagnosis is broad and therefore a systematic approach is of utmost importance to reduce the radiological and disease burden in children and their families. This review article collected current evidence and provides fundamental information for the clinician regarding specific differential diagnoses and unique imaging features of benign liver lesions in children. Ultimately, we propose a practical stepwise approach mainly involving clinical and radiological workup. Laboratory tests and histopathological examination may be necessary in the presence of red flags or in indeterminate lesions.

Scoping review of clinical practice guidelines on the management of benign liver tumours

Objective

Benign liver tumours (BLT) are increasingly diagnosed as incidentalomas. Clinical implications and management vary across and within the different types of BLT. High-quality clinical practice guidelines are needed, because of the many nuances in tumour types, diagnostic modalities, and conservative and invasive management strategies. Yet, available observational evidence is subject to interpretation which may lead to practice variation. Therefore, we aimed to systematically search for available clinical practice guidelines on BLT, to critically appraise them, and to compare management recommendations.

Design

A scoping review was performed within MEDLINE, EMBASE, and Web of Science. All BLT guidelines published in peer-reviewed, and English language journals were eligible for inclusion. Clinical practice guidelines on BLT were analysed, compared, and critically appraised using the Appraisal of Guidelines, Research and Evaluation (AGREE II) checklist regarding hepatic haemangioma, focal nodular hyperplasia (FNH), and hepatocellular adenoma (HCA). Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations (PRISMA) for scoping reviews were adhered to.

Results

The literature search yielded unique 367 papers, 348 were excluded after screening of title/abstract, and 16 after full-text screening. Three guidelines were included: the American College of Gastroenterology (ACG; 2014), Brazilian Society of Hepatology (SBH; 2015), and European Association for the Study of the Liver (EASL; 2016). There was no uniformity in the assessment methods for grading and gravity of recommendations between guidelines. Among observed differences were: (1) indications for biopsy in all three tumours; (2) advices on contraceptive pills and follow-up in FNH and HCA; (3) use of an individualised approach to HCA; (4) absence of recommendations for treatment of HCA in men; and (5) approaches to HCA subtype identification on magnetic resonance imaging.

Conclusion

Recognising differences in recommendations can assist in harmonisation of practice standards and identify unmet needs in research. This may ultimately contribute to improved global patient care.

Behavior and complications of hepatocellular adenoma during pregnancy and puerperium: a retrospective study and systematic review

BACKGROUND

Hepatocellular adenomas (HCA) are benign liver tumors at risk of hemorrhage. The influence of pregnancy on HCA growth and potential bleeding remains unclear. This study investigates HCA-associated behavior and bleeding complications during or shortly after pregnancy.

METHODS

(I) Single center retrospective cohort study of HCA during and after pregnancy (II) Systematic literature review.

RESULTS

The retrospective study included 11 patients, of which 4 with HCA ≥5 cm. In only two patients HCA showed growth during pregnancy. In this local cohort, no HCA-related hemorrhages occurred during median follow-up of 34 months (interquartile range 19-58 months). The systematic review yielded 33 studies, totaling 90 patients with 99 pregnancies. Of 73 pregnancies without prior HCA-related intervention, 39 HCA remained stable (53.4%), 11 regressed (15.1%), and 23 (31.5%) progressed. Fifteen HCA-related hemorrhages occurred in HCA measuring 6.5-17.0 cm. Eight patients experienced bleeding during pregnancy, two during labor and five postpartum.

CONCLUSION

Although hemorrhage of HCA during or shortly after pregnancy is rare and only reported in HCA ≥6.5 cm, it can be fatal. Pregnancy in women with HCA, regardless of size, warrant a close surveillance strategy. Observational studies on behavior and management of HCA ≥5 cm during and immediately after pregnancy are needed.

Analysis of contrast-enhanced ultrasound features of hepatocellular adenoma according to different pathological molecular classifications

OBJECTIVE

To explore the specific contrast-enhanced ultrasound (CEUS) features of hepatocellular adenomas (HCA) according to their pathological molecular classifications.

METHODS & MATERIALS

In this retrospective study, fifty-three histopathologically proved HCA lesions (mean size, 39.7±24.9 mm) were included. Final histopathological diagnosis of HCA lesions were identified by surgical resection (n = 51) or biopsy (n = 2) specimens. CEUS imaging features were compared among four subgroups according to World Health Organization (WHO) 2019 pathological molecular classifications standards. Analysis of variance (ANOVA) were used for statistical analysis of continuous variables. Fisher's exact test were used for categorical variables. The sensitivity (SE), specificity (SP), and accuracy of CEUS feature in diagnosis of each HCA subtype were calculated and compared.

RESULTS

Final histopathological diagnosis included HNF-1α inactivated HCAs (H-HCA, n = 12), β-catenin activated HCAs (B-HCA, n = 8), inflammatory HCAs (I-HCA, n = 31), and unclassified HCAs (U-HCA, n = 2). During arterial phase of CEUS, all HCAs were hyper-enhanced, 66.6% (8/12) of H-HCAs and 50% (4/8) of B-HCAs displayed complete hyperenhancement, whereas 58.0% (18/31) of I-HCAs showed centripetal filling hyperenhancement pattern (P = 0.016). Hyper-enhanced subcapsular arteries could be detected in 64.5% (20/31) I-HCAs during early arterial phase. During portal venous and late phase, sustained hyper- or iso-enhancement were observed in 91.7% (11/12) of H-HCAs, while most of I-HCAs (61.3%, 19/31) and B-HCAs (7/8, 87.5%) were hypo-enhanced (P = 0.000). Central unenhanced areas were most commonly observed in I-HCAs (29.0%, 9/31) (P = 0.034).

CONCLUSION

Depending on its unique imaging features including enhancement filling pattern, hyper-enhanced subcapsular artery and presence of washout, CEUS might provide helpful diagnostic information for preoperative prediction of various HCA molecular subtypes.

Deep learning for differentiation of benign and malignant solid liver lesions on ultrasonography

PURPOSE

The ability to reliably distinguish benign from malignant solid liver lesions on ultrasonography can increase access, decrease costs, and help to better triage patients for biopsy. In this study, we used deep learning to differentiate benign from malignant focal solid liver lesions based on their ultrasound appearance.

METHODS

Among the 596 patients who met the inclusion criteria, there were 911 images of individual liver lesions, of which 535 were malignant and 376 were benign. Our training set contained 660 lesions augmented dynamically during training for a total of 330,000 images; our test set contained 79 images. A neural network with ResNet50 architecture was fine-tuned using pre-trained weights on ImageNet. Non-cystic liver lesions with definite diagnosis by histopathology or MRI were included. Accuracy of the final model was compared with expert interpretation. Two separate datasets were used in training and evaluation, one with all lesions and one with lesions deemed to be of uncertain diagnosis based on the Code Abdomen rating system.

RESULTS

Our model trained on the complete set of all lesions achieved a test accuracy of 0.84 (95% CI 0.74-0.90) compared to expert 1 with a test accuracy of 0.80 (95% CI 0.70-0.87) and expert 2 with a test accuracy of 0.73 (95% CI 0.63-0.82). Our model trained on the uncertain set of lesions achieved a test accuracy of 0.79 (95% CI 0.69-0.87) compared to expert 1 with a test accuracy of 0.70 (95% CI 0.59-0.78) and expert 2 with a test accuracy of 0.66 (95% CI 0.55-0.75). On the uncertain dataset, compared to all experts averaged, the model had higher test accuracy (0.79 vs. 0.68, p = 0.025).

CONCLUSION

Deep learning algorithms proposed in the current study improve differentiation of benign from malignant ultrasound-captured solid liver lesions and perform comparably to expert radiologists. Deep learning tools can potentially be used to improve the accuracy and efficiency of clinical workflows.

[Incidence and characteristics of benign liver space-occupying mass in 17 721 patients with chronic hepatitis B: a color Doppler ultrasound-based case-control study]

OBJECTIVE

To analyze the incidence and risk factors of benign liver space-occupying mass in patients with chronic hepatitis B (CHB) and the ultrasound features that differentiate these masses from small hepatocellular carcinoma.

METHODS

We retrospectively analyzed the color Doppler and clinical data of 17 721 patients with CHB treated in the Hepatology Unit of Nanfang Hospital between January, 2016 and December, 2017. The data were compared with those of 21629 healthy control subjects undergoing routine physical examination in the Center of Heath Management of Nanfang Hospital during the same period.

RESULTS

Compared with the control subjects, the patients with CHB had significantly higher incidences of hepatic cysts (11.8% vs 8.7%, P < 0.05), hepatic hemangioma (8.2% vs 1.6%, P < 0.05) and hepatic cirrhosis nodules (20.6% vs 2.4%, P < 0.05). The incidences of hepatic cysts and cirrhosis nodules increased with age and was significantly higher in male than in female patients (P < 0.001). The highest incidence of hepatic hemangioma was found in CHB patients aged 30-49 years without a gender difference (P>0.05). Sonographically, the benign liver masses commonly showed homogeneous echo within the lesion with clear boundaries and regular shape. Hepatic hemangioma was distinctively hyperechoic in 83.32% (1579/1895) of the patients, while small hepatocellular carcinoma presented with weaker peripheral and internal blood flow signals with a lower flow velocity in the arteries and a higher flow velocity in the portal vein. Liver cirrhosis nodules mostly showed a mixture of strong and weak echoes (79.60%; 7637/9595) without blood flow signal within or around the nodule; an increased volume of the nodule accompanied by heterogeneous echoes within the nodule indicated an increased probability of malignant lesion. Hepatic cysts often displayed no echo within the lesion, but the echo could be enhanced posteriorly.

CONCLUSIONS

The patients with CHB are at a significantly higher risk of developing hepatic cysts, hepatic hemangiomas and hepatic cirrhosis nodules than the control population, and an older age and the male gender are associated with a higher incidence of hepatic cysts or cirrhosis. The differences in the sonographic and hemodynamic features can help to differentiate hepatic benign mass from malignant lesions, and kinetic changes in sonography can be used to monitor potential malignant transformation of the cirrhotic lesions.

Robotic right segmental hepatectomy for the treatment of a giant hepatic hemangioma-a case report

Hemangioma is the most common benign hepatic tumor. We present the case of a patient with a giant symptomatic hemangioma, treated with segmental liver resection using the Da Vinci Robotic System. A 38-year-old woman presented to our surgical out-patient Department complaining about abdominal discomfort and recurrent episodes of acute abdominal pain. CT-scan and MRI imaging of the abdomen revealed the presence of a giant hepatic hemangioma (>5 cm) involving segments VI and VII. Robotic right segmental hepatectomy was performed. The procedure was successfully completed in 120 min and with intraoperative blood loss of only 450 ml. Postoperative period was uneventful and the patient was discharged on the second postoperative day. In case of giant hemangiomas, a minimally invasive robotic major hepatic resection is a viable option that can be performed with minimal complications. A careful preoperative and intraoperative strategy is required, while significant experience in liver and robotic surgery is mandatory.