Benign liver neoplasms

ACG Clinical Guideline: Focal Liver Lesions

Focal liver lesions (FLLs) have become an increasingly common finding on abdominal imaging, especially asymptomatic and incidental liver lesions. Gastroenterologists and hepatologists often see these patients in consultation and make recommendations for management of multiple types of liver lesions, including hepatocellular adenoma, focal nodular hyperplasia, hemangioma, and hepatic cystic lesions including polycystic liver disease. Malignancy is important to consider in the differential diagnosis of FLLs, and healthcare providers must be familiar with the diagnosis and management of FLLs. This American College of Gastroenterology practice guideline uses the best evidence available to make diagnosis and management recommendations for the most common FLLs.

Undifferentiated embryonal sarcoma of liver arising within mesenchymal hamartoma in a child "case report"

Background

Primary pediatric liver tumors are scarce. Undifferentiated embryonal sarcoma of the liver (UESL) embraces nine to fifteen percent of the pediatric hepatic neoplasms. Mesenchymal hamartoma of the liver (MHL) is the second most prevalent benign pediatric hepatic neoplasm following infantile hemangioendothelioma.

Case presentation

A 6-year-old female child presented with vague diffuse abdominal pain and palpable right lumbar mass by clinical examination. The US showed a well-circumscribed large right hepatic complex multilocular cystic lesion with multiple internal septations and some turbid loculi. The constellation of CT and dynamic MRI findings raised the presence of atypical suspicious complex cystic hepatic mass lesion with hemorrhagic, calcific entities and internal soft tissue enhancement. The histopathological correlation proved UESL on the background of MHL.

Conclusions

A case of a pediatric hepatic complex cystic lesion, which had typical ultrasound features of MHL, however, CT and MRI had atypical suspicious criteria. Finally, our case is presented as UESL in the background of MHL based upon pathological diagnosis. The radiologists must be familiar with overlapped entities between MHL, UESL, and other differential diagnosis entities regarding pediatric hepatic neoplasms.

Late hepatic toxicity surveillance for survivors of childhood, adolescent and young adult cancer: Recommendations from the international late effects of childhood cancer guideline harmonization group

BACKGROUND

Survivors of childhood, adolescent and young adult (CAYA) cancer may develop treatment-induced chronic liver disease. Surveillance guidelines can improve survivors' health outcomes. However, current recommendations vary, leading to uncertainty about optimal screening. The International Late Effects of Childhood Cancer Guideline Harmonization Group has developed recommendations for the surveillance of late hepatotoxicity after CAYA cancer.

METHODS

Evidence-based methods based on the GRADE framework were used in guideline development. A multidisciplinary guideline panel performed systematic literature reviews, developed evidence summaries, appraised the evidence, and formulated recommendations on the basis of evidence, clinical judgement, and consideration of benefits versus the harms of the surveillance while allowing for flexibility in implementation across different health care systems.

RESULTS

The guideline strongly recommends a physical examination and measurement of serum liver enzyme concentrations (ALT, AST, gGT, ALP) once at entry into long-term follow-up for survivors treated with radiotherapy potentially exposing the liver (moderate- to high-quality evidence). For survivors treated with busulfan, thioguanine, mercaptopurine, methotrexate, dactinomycin, hematopoietic stem cell transplantation (HSCT), or hepatic surgery, or with a history of chronic viral hepatitis or sinusoidal obstruction syndrome, similar surveillance for late hepatotoxicity once at entry into LTFU is reasonable (low-quality evidence/expert opinion, moderate recommendation). For survivors who have undergone HSCT and/or received multiple red blood cell transfusions, surveillance for iron overload with serum ferritin is strongly recommended once at long-term follow-up entry.

CONCLUSIONS

These evidence-based, internationally-harmonized recommendations for the surveillance of late hepatic toxicity in cancer survivors can inform clinical care and guide future research of health outcomes for CAYA cancer survivors.

Mucinous cystic neoplasm of the liver (MCN-L): a rare presentation and review of the literature

Mucinous cystic neoplasms of the liver (MCN-L, (previously referred to as cystadenomas or cystadenocarcinoma) are rare cystic tumors that occur within the liver parenchyma, or less frequently, in the extrahepatic bile ducts. They are reported to account for <5% of all liver cysts. The differential diagnosis of MCN-L includes intraductal papillary neoplasm of the bile duct (IPNB), intrahepatic cholangiocarcinoma with cystic change, echinococcal cyst, and a simple cyst. Invasive MCNs can only be differentiated from non-invasive MCNs by microscopic evaluation for the presence of ovarian-type stroma. Intraoperative biopsy and frozen section(s) are essential to differentiate MCNs from other cystic liver lesions. The treatment of choice is complete excision and can result in excellent survival with initial correct diagnosis. But its rare presentation and insufficient recognition frequently lead to an incorrect initial or delayed diagnosis or misdiagnosis.

R2* value derived from multi-echo Dixon technique can aid discrimination between benign and malignant focal liver lesions

BACKGROUND

R2* estimation reflects the paramagnetism of the tumor tissue, which may be used to differentiate between benign and malignant liver lesions when contrast agents are contraindicated.

AIM

To investigate whether R2* derived from multi-echo Dixon imaging can aid differentiating benign from malignant focal liver lesions (FLLs) and the impact of 2D region of interest (2D-ROI) and volume of interest (VOI) on the outcomes.

METHODS

We retrospectively enrolled 73 patients with 108 benign or malignant FLLs. All patients underwent conventional abdominal magnetic resonance imaging and multi-echo Dixon imaging. Two radiologists independently measured the mean R2* values of lesions using 2D-ROI and VOI approaches. The Bland–Altman plot was used to determine the interobserver agreement between R2* measurements. Intraclass correlation coefficient (ICC) was used to determine the reliability between the two readers. Mean R2* values were compared between benign and malignant FFLs using the nonparametric Mann–Whitney test. Receiver operating characteristic curve analysis was used to determine the diagnostic performance of R2* in differentiation between benign and malignant FFLs. We compared the diagnostic performance of R2* measured by 2D-ROI and VOI approaches.

RESULTS

This study included 30 benign and 78 malignant FLLs. The interobserver reproducibility of R2* measurements was excellent for the 2D-ROI (ICC = 0.994) and VOI (ICC = 0.998) methods. Bland–Altman analysis also demonstrated excellent agreement. Mean R2* was significantly higher for malignant than benign FFLs as measured by 2D-ROI (P < 0.001) and VOI (P < 0.001). The area under the curve (AUC) of R2* measured by 2D-ROI was 0.884 at a cut-off of 25.2/s, with a sensitivity of 84.6% and specificity of 80.0% for differentiating benign from malignant FFLs. R2* measured by VOI yielded an AUC of 0.875 at a cut-off of 26.7/s in distinguishing benign from malignant FFLs, with a sensitivity of 85.9% and specificity of 76.7%. The AUCs of R2* were not significantly different between the 2D-ROI and VOI methods.

CONCLUSION

R2* derived from multi-echo Dixon imaging whether by 2D-ROI or VOI can aid in differentiation between benign and malignant FLLs.

Biliary Mucinous Cystadenoma: A Review of the Literature

Biliary mucinous cystadenomas are cystic neoplasms commonly mistaken for simple cysts. They are rare and generally benign tumors, often incidentally found on imaging and during unrelated surgical interventions. They tend to be slow growing though may reach symptomatic dimensions. Misdiagnosis of biliary mucinous cystadenomas may have serious consequences secondary to their potential for malignant transformation into biliary mucinous cystadenocarcinomas. Here, we review the epidemiology, etiology, pathology, diagnostic modalities, histology, and available treatment methods for mucinous cystadenomas reported in current literature.

A practical diagnostic approach to hepatic masses

The differential diagnosis of hepatic mass lesions is broad and arriving at the right diagnosis can be challenging, especially on needle biopsies. The differential diagnosis of liver tumors in children is different from adults and is beyond the scope of this review. In adults, the approach varies depending on the age, gender, and presence of background liver disease. The lesions can be divided broadly into primary and metastatic (secondary), and the primary lesions can be further divided into those of hepatocellular origin and nonhepatocellular origin. The first category consists of benign and malignant lesions arising from hepatocytes, while the second category includes biliary, mesenchymal, hematopoietic, and vascular tumors. Discussion of nonepithelial neoplasms is beyond the scope of this review. The hepatocytic lesions comprise dysplastic nodules, focal nodular hyperplasia, hepatic adenoma, and hepatocellular carcinoma, and the differential diagnosis can be challenging requiring clinicopathological correlation and application of immunohistochemical (IHC) markers. Liver is a common site for metastasis, sometimes presenting with an unknown primary site, and proper workup is the key to arriving at the correct diagnosis. The correct diagnosis in this setting requires a systematic approach with attention to histologic features, imaging findings, clinical presentation, and judicious use of IHC markers. The list of antibodies that can be used for this purpose keeps on growing continually. It is important for pathologists to be up to date with the sensitivity and specificity of these markers and their diagnostic role and clinical implications. The purpose of this review is to outline the differential diagnosis of hepatic masses in adults and discuss an algorithmic approach to make a right diagnosis.

Extracapsular excision of hepatic hemangioma: A single centre experience

Backgrounds/Aims

Hepatic hemangioma is a common non-epithelial neoplasm of the liver. Presence of symptoms and uncertainty in diagnosis are the most common indications for surgery.

Methods

Eighteen patients with hepatic hemangioma, operated on from January 2011 to December 2016 at the Hepato-pancreato-biliary surgical unit of Tata Memorial Hospital, were retrospectively analyzed.

Results

Main indications for operation were presence of symptoms, the most common being pain and diagnostic uncertainty. The median size of hemangioma was 9.9 cm (range 3.2 to 24 cm). All patients underwent extra-capsular excision of hemangioma. The median operating time was 180 minutes (range 75 to 460 minutes) and median blood loss was 950 ml (range 100 to 3,500 ml). Median post-operative stay was 5.5 days (range 3 to 10 days). One (5.6%) patient required re-exploration for post-operative hemorrhage, Clavien Dindo (CD) grade IIIb, and one (5.6%) had postoperative purulent intra-abdominal collection requiring percutaneous cutaneous drainage CD grade IIIa. There was no postoperative mortality. Postoperative day 3 liver function tests were within normal limits. Size of the tumor did not correlate significantly with postoperative complications (p=0.135).

Conclusions

Surgical treatment of hemangioma should be guided by presence of symptoms or by the presence of diagnostic uncertainty, not by size alone. The size had no correlation with perioperative complications. The technique of extra-capsular excision is safe and technically feasible in most of the hemangiomas. This technique preserves maximum liver parenchyma, resulting in early postoperative recovery with minimal morbidity.

National trends in the use of surgery for benign hepatic tumors in the United States

BACKGROUND

The widespread use of diagnostic imaging has led to an increase in the incidence and diagnosis of benign liver tumors. The objective of this study was to define the overall use and temporal trends of operative procedures for benign liver tumors using a nationally representative cohort.

METHODS

All patients who underwent liver surgery for benign liver tumors between 2000 and 2011 were identified from the Nationwide Inpatient Sample database. Trends in annual volume of liver procedures were analyzed using the average annual percent change (AAPC) assessed by joinpoint analysis.

RESULTS

There were 2,489 open (94.5%) and 144 (5.5%) minimally invasive surgical (MIS) procedures. Partial hepatectomy accounted for 43.8% of all cases (n = 1,153). Surgery for patients with benign liver tumors increased from 156 in 2000 to 272 in 2011 (AAPC, 5.8%; 95% CI, 3.2-8.6%). There was decline in the relative use of open operative procedures from 98.1% in 2000 to 92.3% in 2011 (AAPC, -0.4%; 95% CI, -0.7 to -0.1%). In contrast, the proportion of MIS procedures increased from 1.9% in 2000 to 7.7% in 2011 (AAPC, 7.4%; 95% CI, 1.9-13.3%). The median duration of stay among all patients was 5 days (interquartile range, 4-7; 5 days [open] vs 3 days [MIS]; P < .001). Inpatient mortality was 0.6% (n = 15 [open] vs n = 0 [MIS]; P = .43) and did not change during the study period (P > .05).

CONCLUSION

Overall volume of surgical management of benign liver tumors has increased substantially over the past decade. There has been a relative shift away from open procedures toward MIS procedures.

What is changing in indications and treatment of hepatic hemangiomas. A review

Hepatic cavernous hemangioma accounts for 73% of all benign liver tumors with a frequency of 0.4-7.3% at autopsy and is the second most common tumor seen in the liver after metastases. Patients affected by hemangioma usually have their tumor diagnosed by ultrasound abdominal examination for a not well defined pain, but pain persist after treatment of the hemangioma. The causes of pain can be various gastrointestinal pathologies including cholelithiasis and peptic ulcer disease.The malignant trasformation is practically inexistent. Different imaging modalities are used to diagnosis liver hemangioma including ultrasonography, computed tomography (CT), magnetic resonance (MR) imaging, and less frequently scintigraphy, positronemission tomography combined with CT (PET/CT) and angiography. Imaging-guided biopsy of hemangioma is usually not resorted to except in extremely atypical cases. The right indications for surgery remain rupture, intratumoral bleeding, Kasabach-Merritt syndrome and organ or vessels compression (gastric outlet obstruction, Budd-Chiari syndrome, etc.) represents the valid indication for surgery and at the same time they are all complications of the tumor itself. The size of the tumor do not represent a valid indication for treatment. Liver hemangiomas, when indication exist, have to be treated firstly by surgery (hepatic resection or enucleation, open, laproscopic or robotic), but in the recent years other therapies like liver transplantation, radiofrequency ablation, radiotherapy, trans-arterial embolization, and chemotherapy have been applied.

Defining vascular signatures of benign hepatic masses: role of MDCT with 3D rendering

Multidetector CT (MDCT) provides new opportunities for hepatic tumor characterization. By coupling high-resolution isotropic datasets with advanced post-processing tools, maps of tumor vascularity can be generated to elucidate characteristic findings. This two-part review describes a range of benign and malignant liver masses, with emphasis on IV contrast-enhanced MDCT features and vascular signatures that can be identified on 3D vascular mapping.

Indicação e tratamento dos tumores benignos do fígado

INTRODUÇÃO: Os tumores hepáticos benignos ocorrem em 9% da população. A grande maioria dessas neoplasias é diagnosticada em pacientes assintomáticos durante a realização de exames de imagem de rotina. OBJETIVO: Apresentar os principais aspectos das indicações e tratamento dos tumores hepáticos benignos. MÉTODOS: Foi realizada revisão de literatura baseada em pesquisa no PubMed, Bireme e Scielo cruzando os descritores neoplasia hepática, hemangioma, adenoma e hiperplasia nodular focal. Foram selecionados, estudos de técnicas cirúrgicas e acrescentada a experiência dos autores. O hemangioma é o tumor hepático mais comum, sendo identificado entre 5% e 7% das necropsias. É mais comum nas mulheres entre as 3ª e 5ª décadas da vida e pode aumentar de tamanho na gravidez e com a administração de estrogênios. Apesar de não estabelecida, a sua causa está relacionada com os hormônios sexuais. As complicações incluem inflamação, coagulopatia, sangramento e compressão de estruturas vizinhas. Rotura espontânea é excepcional, com somente 35 casos descritos na literatura internacional. O adenoma e a hiperplasia nodular focal predominam no sexo feminino e na faixa etária de 20 a 40 anos. Enquanto o primeiro requer ressecção hepática pelo risco de sangramento e malignização, o segundo deve ter conduta expectante. CONCLUSÕES: Os tumores hepáticos benignos mais comuns são em ordem decrescente de frequência o hemangioma, hiperplasia nodular focal e o adenoma. A diferenciação entre tumores benignos e malignos é geralmente realizada com segurança com base nos dados clínicos e nos exames de imagem. O hemangioma e a hiperplasia nodular focal geralmente tem conduta expectante, enquanto que o adenoma requer ressecção pelo risco de hemorragia e de transformação em carcinoma.

Radiofrequency ablation combined with percutaneous ethanol injection in patients with hepatocellular carcinoma

BACKGROUND AND STUDY AIMS

Hepatocellular carcinoma (HCC) is a major burden on health-care systems worldwide. Although radiofrequency ablation (RFA) is currently considered the best technique for coagulative necrosis, the superiority of concomitant use of RFA and percutaneous ethanol injection (PEI) needs to be determined. The study was designed to compare efficacy, safety and rate of survival of patients with HCC assigned to receive combined PEI-RFA versus RFA alone and versus PEI alone.

PATIENTS AND METHODS

This 3-year study enrolled 90 cirrhotic patients with HCC (Child's class A or B, but not class C). They were randomly assigned for either PEI-RFA (group I), RFA alone (group II) or PEI alone (group III). The primary end point was ablation of the tumour. The secondary end point was rate of survival and recurrence.

RESULTS

After the first session, complete ablation was significantly higher in the combination group (87.9%) compared with the RFA group (54.54%). After the second session, complete ablation was achieved in 97.0% of the combination group and in 84.8% of the RFA group. Regarding the PEI group, 75% had complete ablation, whereas 25% had partial ablation after multiple sessions. The survival rate, 1.5 years later, was significantly higher in group I (86.7%) compared with group III (63.3%). The overall incidence of serious adverse events was nil.

CONCLUSION

Combined treatment is superior to RFA alone and to PEI alone, in safety and efficacy in patients with HCC.

Reappraisal of surgical indications and approach for liver hemangioma: single-center experience on 74 patients

BACKGROUND

Liver hemangiomas are rarely large, symptomatic, or presenting atypical imaging patterns. Surgery is rarely needed; indications and choice of the best technique remain not precisely defined.

METHODS

Features of hemangiomas and surgical indications were assessed in 74 patients (mean follow-up 63.2 months). In 40 operated patients, the results of liver resection versus enucleation were compared.

RESULTS

Most hemangiomas (60/74, 81.1%) showed no size increment. In 40 operated patients (40/74, 54.1%) the mean tumor size (11.9 cm, range 2.6-46.0) was larger than in nonoperated patients (11.9 vs 6.0 cm, P = .0002). Surgical indications were specific symptoms, tumor enlargement, Kasabach-Merritt syndrome, and uncertain diagnosis. Mortality (nil), morbidity (10.0%), and transfusion rate (15.0%) were similar for 28 liver resections versus 12 enucleations; bleeding was more related to large hemangioma size than to the choice of either technique. Liver ischemia techniques, autotransfusion, and intraoperative blood salvage reduced the risk of transfusion.

CONCLUSIONS

Surgery is rarely indicated, has a low risk, and has similar results for liver resection versus enucleation. Risk of bleeding is related more to the large size of the hemangioma than to the type of surgery (resection or enucleation). In these patients, management, the need for surgery, and the choice of technique should be carefully individualized.

From the archives of the AFIP: Pediatric liver masses: radiologic-pathologic correlation part 1. Benign tumors

Benign hepatic tumors in children include lesions that are unique to the pediatric age group and others that are more common in adults. Infantile hemangioendothelioma, or infantile hepatic hemangioma, is a benign vascular tumor that may cause serious clinical complications. It is composed of vascular channels lined by endothelial cells. At imaging, large feeding arteries and draining veins and early, intense, peripheral nodular enhancement with centripetal filling on delayed images are characteristic features. Mesenchymal hamartoma of the liver occurs in young children and is characterized pathologically by mesenchymal proliferation with fluid-containing cysts of varying size and number. The mesenchymal component or cystic component may predominate; this predominance determines the imaging appearance of the tumor. Benign epithelial tumors that are common in adults may infrequently occur in childhood. These include focal nodular hyperplasia (FNH), hepatocellular adenoma, and nodular regenerative hyperplasia. All are composed of hyperplastic hepatocytes similar to surrounding liver parenchyma and may be difficult to discern at imaging. Preferential hepatic arterial phase enhancement helps distinguish FNH and hepatic adenoma from uninvolved liver. Hepatic adenoma often has intracellular fat and a propensity for intratumoral hemorrhage, neither of which are seen in FNH. Unlike adenoma, FNH often contains enough Kupffer cells to show uptake at sulfur colloid scintigraphy. Nodular regenerative hyperplasia is often associated with portal hypertension, which may be evident at imaging. Knowledge of how the pathologic features of these tumors affect their imaging appearances helps radiologists offer an appropriate differential diagnosis and management plan.

Diagnosis and treatment of benign focal liver lesions

BACKGROUND

With the routine use of improved imaging modalities, more benign liver lesions are detected nowadays. An accurate characterization of these incidental lesions may be a challenge, and frequently a biopsy or even unnecessary surgery is being performed. However, these interventions are not always to the benefit of the patient.

METHODS

A Medline search of studies relevant to imaging diagnosis and management of the most common, benign, solid and non-solid liver lesions was undertaken. References from identified articles were handsearched for further relevant articles. The authors' own experiences with benign liver lesions were also taken into account.

RESULTS

Although atypical imaging features are the exception rather than the rule, it is sometimes difficult to differentiate between benign and malignant lesions, and knowledge of their imaging features is essential if unnecessary work-up is to be avoided. The use of tissue-specific contrast media, which has clearly improved the accuracy of highly advanced radiological techniques, may be helpful during differential diagnosis. Once having established an accurate diagnosis, surgery is rarely indicated for a benign liver lesion because of its asymptomatic nature.

CONCLUSION

Knowledge of imaging features and a clear management strategy during diagnostic work-up, emphasizing the indications for surgery, will minimize the number of patients who have to undergo biopsy or unnecessary surgery.

[Surgical therapy of benign liver tumors]

Benign liver tumors are being detected more frequently due to the widespread use of ultrasound and complementary methods and due to improvements in diagnostic accuracy. In the case of a reliable diagnosis of asymptomatic hemangioma or focal nodular hyperplasia surgery is not indicated. Hepatic adenoma of considerable size should be resected primarily based on the risk of rupture. Improvements in diagnostic imaging as well as the optimization of surgical procedures with extremely low complication rates permit an individualized management strategy founded on evidence-based algorithms. In the case of an equivocal diagnosis, we advocate low-risk tumor resection instead of tumor biopsy due to the inherent complication rates of hemorrhage or tumor-cell dissemination and possible misleading histology.

Incidental reduction in the size of liver hemangioma following use of VEGF inhibitor bevacizumab

BACKGROUND/AIMS

Hepatic cavernous hemangioma is the second most common liver tumor after metastases. Vascular endothelial growth factor (VEGF) is recognized as an essential regulator of blood vessel growth. High VEGF expression leads to increased angiogenic activity in cavernous hemangioma endothelial cells. The use of specific antibodies directed against VEGF abolishes this vascular endothelial growth-promoting activity in vitro. Bevacizumab is a recombinant humanized monoclonal antibody directed against VEGF which is used for the treatment of metastatic colorectal cancer in combination with 5-fluorouracil-based regimens.

METHODS

We report a patient with invasive colorectal adenocarcinoma and suspected liver metastasis on radiological examination, who showed a significant decrease in the size of his liver lesions after bevacizumab treatment. Histology of the liver lesions revealed hemangioma with a strong staining for VEGF and anti-VEGFr2 antibody in the hemangioma endothelial cells. To date, surgical resection provides the only consistently effective method for treatment of hepatic hemangioma.

CONCLUSIONS

This is the first documented case of hepatic hemangioma responsive to antiangiogenic therapy, suggesting a possible use for these agents in treating symptomatic patients without surgery. VEGF-signaling blockade including bevacizumab use poses a potential new treatment modality for vascular neoplasms in the liver and other sites.

Mesenchymal hamartoma of the liver accompanied by a daughter nodule: report of a case

Mesenchymal hamartoma of the liver (MHL) is an uncommon benign tumor found primarily in children younger than 2 years of age. We report a rare case of MHL with a daughter nodule and atypical histological findings in a 14-month-old girl. On admission, computed tomography, magnetic resonance imaging, and angiography showed a solid hypovascular mass with a central cystic area in the liver. Laparotomy revealed a tumor, 8 cm in size, occupying segment 5 and parts of segments 4 and 6 of the liver, and a small nodule, 10 mm in size, in segment 7. Thus, we performed a partial hepatic resection (S4-6) and tumor extirpation (S7). The histological findings of both tumors were the same, but atypical of MHL. Recent studies on the pathogenesis of this tumor have found neoplastic features such as genetic anomalies and malignant transformation. These findings suggest that the conventional approach of completely resecting the tumor whenever possible is the best treatment.

Focal liver masses: enhancement patterns on contrast-enhanced images--concordance of US scans with CT scans and MR images

PURPOSE

To assess prospectively the concordance of enhancement patterns of focal liver masses on contrast material-enhanced ultrasonographic (US) scans with patterns on contrast-enhanced computed tomographic (CT) scans or magnetic resonance (MR) images.

MATERIALS AND METHODS

This study was approved by the institutional review board; patients gave informed consent. Contrast-enhanced US and contrast-enhanced CT or MR imaging were performed in 135 patients (62 men, 73 women; mean age, 51 years) with 144 confirmed liver masses. Masses included 49 hepatocellular carcinomas, 13 metastases, 30 hemangiomas, 41 lesions of focal nodular hyperplasia, and 11 others. Randomized image sets from each modality were shown independently to three blinded readers, who answered identical questions about enhancement of the lesion and liver in the arterial and portal venous phases and changes with time. Concordance for modalities was calculated from answers of readers and consensus answers between readers, with 95% confidence intervals (CIs). The kappa values were calculated for interreader agreement.

RESULTS

Features of arterial phase enhancement showed concordance of more than 76% for modalities. The highest concordance of 92% (132 of 144), with 95% CI of 86% and 95% (kappa>0.84), was for the presence of peripheral pools and centripetal progression. Concordance in the portal venous phase was lower, with agreement for predominant enhancement of the lesion in 61% (86 of 142), with 95% CI of 52% and 68% (kappa>0.83). Portal venous phase washout occurred in 75% (106 of 142), with 95% CI of 67% and 81% (kappa>0.81). The majority of discordances were for malignancies for which only US depicted no sustained enhancement in the portal venous phase.

CONCLUSION

US shows high concordance with CT or MR imaging, especially for the arterial phase. Discordance in the portal venous phase may reflect the tendency of CT and MR contrast agents, unlike microbubbles, to diffuse into interstitium.

Evaluation of nonmalignant liver masses

Nonmalignant liver masses are increasingly being recognized with the widespread use of imaging modalities such as ultrasonography, computed tomography, and magnetic resonance imaging. The majority of these lesions are detected incidentally in asymptomatic patients. Based on the radiologic appearance, benign lesions can be categorized as solid or cystic, single or multiple, hypervascular or hypovascular. Based on histologic characteristics, they are classified as of hepatocellular, biliary, or mesenchymal origin. In the majority of patients, a proper diagnosis can be made based on these characteristics on imaging modalities alone. An invasive approach is seldom required. This review discusses the various characteristics of the most common benign liver lesions and recommends a practical approach.

The diagnosis and management of benign hepatic tumors

Benign hepatic tumors include a broad spectrum of regenerative and true neoplastic processes. Because of advances in imaging studies such as computed tomography (CT) and magnetic resonance imaging (MRI) as well as progress in immunohistochemistry, accurate diagnosis can now be made in a large percentage of patients without surgical laparotomy or resection. This article will focus on the pathogenesis, diagnosis, and management of focal benign lesions of the liver. Many of these tumors present with typical features in various imaging studies. On occasions, biopsies are required and/or surgical removal is needed. The most common benign hepatic tumors include cavernous hemangioma, focal nodular hyperplasia, hepatic adenoma, and nodular regenerative hyperplasia. In the majority of cases of benign hepatic tumors, patients are asymptomatic, and no treatment is indicated. The main indication for treatment is the presence of significant clinical symptoms or suspicion of malignancy or fear of malignant transformation.

Oral contraceptives and liver hemangioma: a case-control study

OBJECTIVE

To study whether there is an epidemiological association between liver hemangiomas and oral contraception use, as may be suggested by clinical observations of liver hemangioma growth during pregnancy and under estrogen administration.

METHODS

A case-control study of 40 women with liver hemangiomas, as diagnosed by imaging studies [ultrasonography (US) or computed tomography (CT) and nuclear scan], and 109 age-matched control with normal studies. The women were interviewed with respect to their menstrual, reproductive and oral contraception use history.

RESULTS

The liver hemangioma and control groups did not differ significantly with regard to their menstrual or reproductive history. Ever oral contraception use was reported by 30% of the cases and 27% of controls. The odds ratio (OR) was 1.1 [95% confidence interval (CI) 0.52-2.60] for ever use, 1.64 (95% CI 0.37-7.13) for initiation before the age of 20, and 0.62 (95% CI 0.16-2.42) for use duration of less than 1 year. On the multivariate analysis only the women's age emerged as a predictor for liver hemangiomas (OR 3.1; 95% CI 1.16-8.96).

CONCLUSIONS

In this study liver hemangiomas were not associated with menstrual, reproductive and oral contraception use history.

Spontaneous intraperitoneal hemorrhage: imaging features

Spontaneous intraperitoneal bleeding can result from a vast array of etiologies. Fortunately, most are uncommon and currently available imaging modalities can be used to differentiate them in almost all cases. Meticulous imaging technique and careful observation of key imaging features are important for accurate characterization of the organ of origin of the spontaneous bleeding. CT is the single most important imaging technique in the detection and characterization of spontaneous intraperitoneal bleeding. Further development in multidetector technology, such as the introduction of new machines with 8 or 16 detectors, should improve the effectiveness of CT further. Sonography and MR imaging are complimentary to CT, especially in patients with pelvic abnormalities or equivocal CT findings.