Search

Benign liver lesions are among the most commonly diagnosed abnormalities in liver imaging. They are often discovered incidentally during routine examinations or imaging conducted for unrelated reasons. These can be solid lesions, such as hemangiomas, focal nodular hyperplasia, hepatic adenomas, or cystic lesions. Recent advancements in MRI technology, particularly with hepatocyte-specific contrast agents, have enhanced the characterization of these lesions, reducing the reliance on invasive tissue sampling. Nevertheless, tissue sampling retains a crucial role in the evaluation of indeterminate lesions or those with malignant potential. While most benign liver lesions are asymptomatic, some can become symptomatic, causing discomfort, pain, or bleeding, particularly if the lesion is large. A deep understanding of the molecular underpinnings of the lesions is crucial for tailoring patient management strategies, particularly in distinguishing lesions that require surgical intervention from those that can be monitored. For instance, the molecular subclassification of hepatic adenomas has provided mechanistic insights and identified certain subtypes that are at higher risk of malignancy. Most benign liver lesions can be safely monitored; however, in patients with cirrhosis or a known primary malignancy, a high index of suspicion for cancer is required. It is crucial to carefully evaluate any liver lesion identified in these patients to ensure that indeterminate lesions are not overlooked. Effective management of benign liver lesions involves a multidisciplinary team, including hepatologists, surgeons, and radiologists, ensuring a comprehensive and individualized approach to patient care. This review outlines the clinical presentation of common benign liver lesions, providing a diagnostic and management framework. Emphasis is placed on a personalized approach to minimize patient distress and optimize outcomes by leveraging imaging advancements and multidisciplinary collaboration., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Association for the Study of Liver Diseases.)

Rationale: Multilocular cystic hemangioma is a rare benign tumor classified as an atypical hemangioma. Currently, there are limited imaging reports available, and the imaging characteristics can be challenging to distinguish from other malignant multilocular cystic liver diseases such as cystadenocarcinoma, necessitating confirmation through pathological diagnosis. Here, we discuss the imaging features of 3 cases of multilocular cystic hemangiomas., Patient Concerns and Diagnoses: Case 1 was a 24-year-old young female, and Case 2 involved a 60-year-old elderly male. Both patients were asymptomatic and physical examination revealed hepatic space-occupying lesions. Imaging findings revealed multilocular cystic lesions in the left liver with septa, calcification, a high diffusion-weighted magnetic resonance imaging (DWI) signal at the edge of the lesion, and progressive enhancement of the cyst wall and septa. Case 3 involved a 50-year-old male patient with epigastric distending pain for 1 month and sudden severe abdominal pain for 14 hours. Imaging results revealed a multilocular cystic lesion in the left liver with septa and tumor bleeding, a high DWI signal, and an enhanced cyst wall and septa. The pathological diagnosis confirmed a hepatic hemangioma., Interventions: All 3 patients underwent liver tumor resection., Outcomes: All 3 patients recovered successfully without any intraoperative or postoperative complications during the follow-up periods of 5 years, 6 months, and 5 months. There were no signs of recurrence., Lessons: Liver imaging revealed multilocular cystic lesions with features, such as compartmentalization, calcification, or bleeding. Multilocular cystic hemangiomas should be considered in imaging diagnosis. Enhancing our understanding of multilocular cystic hemangiomas can aid in improving the differential diagnosis of other malignant multilocular cystic liver diseases, ultimately reducing unnecessary liver resection., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

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., (Copyright © 2024 by The American College of Gastroenterology.)

Introduction: To decide treatment of hepatic cysts diagnosis between simple hepatic cyst (SHC) and cystic mucinous neoplasm (CMN). Radiological features are not patognomonic. Some studies have suggested the utility of intracystic tumor markers., Methods: Retrospective analysis of our prospective database including patients treated due to symptomatic SHC from 2003 to 2021. The aim of the study was to evaluate the results of treatment of symptomatic SHC and the usefulness of the determination of intracystic "carcinoembryonic antigen" (CEA) and "carbohydrate antigen" CA 19.9., Results: 50 patients diagnosed and treated for symptomatic SHC were included. In 15 patients the first treatment was percutaneous drainage. In 35 patients the first treatment was laparoscopic fenestration. Four patients were diagnosed of premalignant or malignant liver cystic lesions (MCN, IPMN, lymphoma B); three of them required surgery after initial fenestration and pathological diagnosis. Median CEA and CA 19-9 were 196 μg/L and 227.321 U/mL respectively. Patients with malignant or premalignant pathology did not have higher levels of intracystic tumor markers. Positive predictive value was 0% for both markers, and negative predictive value was 89% and 91% respectively., Conclusion: Values of intracystic tumor markers CEA and CA 19-9 do not allow distinguishing simple cysts from cystic liver neoplasms. The most effective treatment for symptomatic simple liver cysts is surgical fenestration. The pathological analysis of the wall of the cysts enables the correct diagnosis, allowing to indicate a surgical reintervention in cases of hepatic cyst neoplasia., (Copyright © 2023. Published by Elsevier España, S.L.U.)

Cystic hepatic lesions encompass a vast spectrum of infectious, non-neoplastic, and neoplastic entities. Most hepatic cysts are benign and asymptomatic, requiring no active intervention. However, symptomatic and malignant cysts need proper evaluation and specific treatment. An accurate preoperative diagnosis is pivotal for patient management. At times, these lesions may mimic, especially symptomatology and radiology, leading to a diagnostic ordeal. We herein present a case of a patient with cystic liver lesions in a treatment naïve neuroendocrine tumor that was a diagnostic dilemma on radiology. Low cellularity of cytology smears made the diagnosis challenging, and cell block immunocytochemistry finally clinched the diagnosis. A timely diagnosis provided on cytology fuelled further work-up, the discovery of primary tumor, and initiation of appropriate therapy., (© 2022 Wiley Periodicals LLC.)

The diagnosis of cystic liver disease has made great progress with the advent of enhanced imaging techniques. At the same time, its management has gradually improved over the past few decades, providing the basis for the development of appropriate diagnostic and treatment guidelines. To this end, the European Association for the Study of the Liver has developed clinical guidelines for the diagnosis and treatment of non-infectious cystic liver disease. This guideline put forward recommendations based on an in-depth review of the relevant literature for addressing clinical issues, including the diagnosis and treament of hepatic cysts, hepatic mucocystic tumors, biliary hamartomas, polycystic liver disease, Caroli disease or Caroli syndrome, biliary hamartomas, and peribiliary cyst.

Cystic liver lesions (CLL) are common and, in the majority of cases, benign. However, the range of differential diagnoses of CLL is wide. A combination of medical history, blood test results, and imaging can help find the correct diagnosis. We report the case of a 38-year-old immunocompromised female patient with a history of thymectomy and postoperative radiation 3 years prior due to thymoma. Subsequently, the patient was referred to our department for clarification of a cystic liver lesion. During short-term follow-up, the lesion increased in size, and due to the contrast agent behavior in the ultrasound and MRI examination, the suspicion of a biliary cystadenocarcinoma was considered.Furthermore, imaging showed several subcentimetric liver lesions of unknown dignity. Finally, pericystectomy and atypical partial liver resection was performed. Histology revealed a cystic metastasis of the malignant B3 thymoma and a cavernous hemangioma. Liver metastases of a thymoma are rare, and this is the first case of a cystic liver metastasis of a thymoma. The presented case illustrates that in the management of CLLs beside imaging techniques, the medical history with previous conditions should be considered, especially in past malignancies., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Hepatocellular benign liver tumours are mainly developed on normal liver and include hepatic hemangioma, focal nodular hyperplasia and hepatocellular adenoma from the most frequent to the less frequent. The diagnosis of hepatic hemangioma and of simple hepatic biliary cysts can be performed using non-invasive criteria using liver ultrasonography or contrast enhanced MRI. Most of the time the diagnosis of focal nodular hyperplasia can be achieved using contrast-enhanced ultrasonography or contrast enhanced MRI with an additional value of hepatobiliary contrast-agent in this setting. Rarely, if a doubt persists, a tumour and non-tumour liver biopsy can be required in order to establish the diagnosis. As hepatic hemangioma, simple hepatic biliary cysts and focal nodular hyperplasia are not associated with complications, they don't require any treatments or follow-up. Hepatocellular adenomas are mainly diagnosed at histology on surgical samples or liver biopsy even if some radiological features are highly suggestive of several subtypes of hepatocellular adenomas. Finally, the management of hepatocellular adenomas should be guided according to the tumour size, gender but also to the molecular subtypes., Competing Interests: Declaration of Competing Interest None., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Abdominal ultrasound in a 50-year-old Japanese man revealed a cystic lesion on the caudate lobe of the liver. Four-month follow-up imaging showed a rapid increase in the size of the cystic lesion. The patient underwent laparoscopic partial hepatectomy because of a suspicion and perceived risk that the lesion might be malignant. The initial histological diagnosis was a hepatic cyst. Eleven months later, computed tomography showed a giant cystic lesion in the abdominal cavity and multiple liver metastases. The patient underwent excision of the giant cystic lesion and a partial hepatectomy. Immunohistochemistry for the recurring lesion revealed undifferentiated embryonal sarcoma of the liver.

Case: A 77-year-old woman was referred to our hospital for detailed examination of a cystic liver tumor. Contrast-enhanced CT and MRIshowed a cystic liver tumor with an enhanced mural nodule in S6 of the liver. Under a preoperative diagnosis of hemorrhagic hepatic cyst and mucinous cystic neoplasm(MCN)of the liver, extended posterior segmentectomy was performed. Histological examination of the tumor revealed no neoplastic cells, and the tumor was finally diagnosed as a hemorrhagic hepatic cyst of the liver., Conclusion: Similar to previous reports of hemorrhagic hepatic cysts, preoperative differential diagnosis from MCN of the liver was difficult in this case. Hemorrhagic hepatic cysts are rare and are sometimes confused with MCN of the liver, especially when an enhanced mural nodule is found in the cyst. The possibility of hemorrhagic hepatic cysts should be considered during diagnosis of liver cystic tumors.

Benign liver tumors form a heterogeneous group. The most frequent forms include simple cysts, hemangiomas, focal nodular hyperplasia and hepatocellular adenomas. They are often incidentally detected during routine sonography. The diagnosis of a liver tumor not uncommonly causes anxiety and insecurity in those affected, which is why a rapid and reliable diagnostic procedure should be carried out. Because some tumors, particularly hepatocellular adenomas, are of prognostic relevance due to the potential risk of malignant transformation, a correct classification should always be strived for. The type and extent of diagnostic clarification depend on the clinical and patient-related risk factors. This article describes the most important benign space-occupying lesions. The etiology, clinical manifestations and diagnostics as well as possible necessary treatment measures are presented.

Background: Polycystic liver disease (PCLD) with a large cystic volume deteriorates the quality of life of patients through substantial effects on the adjacent organs, recurrent cyst infections, cyst rupture, and hemorrhage. Surgical or radiological intervention is usually needed to alleviate these symptoms. We report a rare case of the cystic metastasis of renal cell carcinoma (RCC), which was misdiagnosed as PCLD, as a result of the clinical and radiological similarity between these disorders., Case Summary: A 74-year-old female who had undergone nephrectomy for papillary-type RCC (PRCC) was suffering from abdominal pain and the recurrent intracystic hemorrhage of multiple cysts in the liver. Imaging studies and aspiration cytology of the cysts showed no evidence of malignancy. With a diagnosis of autosomal dominant polycystic liver disease, the patient received hepatectomy for the purpose of mass reduction and infectious cyst removal. Surgery was performed without complications, and the patient was discharged on postoperative day 14. Postoperatively, the pathology revealed a diagnosis of recurrent PRCC with cystic formation., Conclusion: This case demonstrates the importance of excluding the cystic metastasis of a cancer when liver cysts are observed., Competing Interests: Conflict-of-interest statement: The authors declare that they have no conflicts of interest.

Solid pseudopapillary neoplasm (SPN) of the pancreas is considered a low-malignant neoplasm with a good prognosis. However, 5% to 15% of patients with SPNs develop metastatic disease, most commonly in the liver. Metastatic hepatic malignancies that show pseudocystic features are rare. Here we describe the case of a middle-aged female with a cystic liver metastasis from SPN. To the best of our knowledge, SPN with a single cystic liver metastasis has not been described, although these tumours frequently undergo haemorrhagic-cystic degeneration. Thus, in these patients the marked cystic change could be misinterpreted as a benign lesion.

The aim of this study was to examine the possibilities of measuring ADC/DWI values with the ROI method for precise differentiation of focal liver lesions from normal liver parenchyma. The study included 100 liver lesions sized ≥1 cm, previously detected in patients by ultrasound and computed tomography. It is done by measuring the diffusion coefficient ADC folder (MRI 3T), setting the ROI on the periphery of hepatic lesions, on the liver parenchyma around the focal hepatic lesions and on liver parenchyma that is distant to hepatic lesions. In our study, difference between the average ADC value of focal liver lesions (1.24 x10(-3) mm(2)/s) and normal liver parenchyma around focal liver lesions (1.001x10(-3) mm(2)/s) was statistically confirmed. There was statistically proven difference in the average ADC values between normal liver parenchyma around focal lesions and liver parenchyma located distant from focal lesions of (1.003x10-3 mm2/s). Wilcoxon rank test yielded differences in the average (median) ADC values between total lesions in patients and liver parenchyma directly around focal lesions (p<0.0005). Wilcoxon rank test showed no differences in the average (median) ADC between liver parenchyma directly around focal lesions and distant of focal hepatic lesions (p<0.0005). The results obtained for each focal liver lesion were compared with histopathology findings obtained by puncture or surgery, and for cystic lesions radiological follow up was sufficient. For all liver lesions, the resulting overall DWI/ADC sensitivity was 92% and specificity 77%. Kendall’s tau-b coefficient of concordance showed a statistically significant correlation between our DWI diagnosis and histopathology verification for all liver lesions (p<0.0005). He mangiomas and cysts showed greatest difference in ADC values as compared with healthy liver. ADC values of hepatocellular carcinoma (HCC) and the surrounding normal liver parenchyma were not statistically different, which can be explained by similarities in their cell structure. Related articles conclude that DWI has inadequate sensitivity in detecting HCC, explaining this minimal difference in cellularity of well differentiated HCC and liver parenchyma. DWI/ADC has the potential to differentiate and reliably define the limits of focal lesions of the normal liver parenchyma. ADC delimitation of focal lesions of the liver parenchyma is most reliable for hemangiomas and cysts, while ADC delimitation of HCC can pose diagnostic difficulties.

Due to the expanding use of diagnostic imaging, an increasing number of liver tumours are discovered. Benign tumours are very common; they rarely cause symptoms and often they do not require any treatment. However, because of differences in the natural history including risk of complications and malignant transformation exact diagnosis is important. Dedicated radiological examinations serve as important diagnostic tools reducing the need for biopsy. In this review we provide an update on the diagnosis and treatment of benign liver tumours adding to existing recommendations on hepatocellular carcinomas and adenomas.

Purpose: To compare low b value (10s/mm(2)) spin-echo echo-planar (SE-EP) diffusion-weighted imaging (DWI) acquired with respiratory-triggering (RT), triggering and tracking navigator (TT), tracking only navigator (TRON) techniques for image quality and focal liver lesions (FLL) detection in non-cirrhotic patients., Material and Methods: This bi-centric study was approved by the institutional review boards; informed consent was obtained. Eighty-three patients were prospectively included and SE-EP-DWI with RT, TT and TRON techniques were performed. DWI sequences were randomized and independently analyzed by two readers. The qualitative evaluation was based on a 3-point score for axial artifacts (motion, ghost, susceptibility artifacts and distortion) and stair-step artifacts. Sensitivity of FLL detection was calculated for all lesions together and after lesion size stratification (≤ 10 mm, >10-20mm and >20mm). The standard of reference consisted of a retrospective reading of the conventional MRI, the three DWI sequences and by follow-up (12 months): a total of 409 FLL were detected. Data between sequences was compared with non-parametric tests. Cohen's kappa coefficient was used for inter-observer agreement., Results: Image quality was comparable for RT and TT. TRON showed statistically significantly more axial artifacts for the two readers (p<0.05). Stair-step artifacts were not statistically significantly different between DWI sequences. Overall sensitivities for RT, TT, TRON were 85%, 86%, 82% and 86%, 89% 83%, respectively, for readers 1 and 2. The inter-observer agreement was very good., Conclusion: Image quality was better for RT and TT compared to TRON. Overall sensitivities for FLL detection were comparable between techniques and readers., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Background: The initial abdominal computed tomography (CT) scans of patients with colorectal cancer (CRC) sometimes reveal equivocal hepatic lesions. In this study, we evaluated the outcomes of equivocal hepatic lesions found by abdominal CT and the diagnostic accuracy of subsequent liver magnetic resonance imaging (MRI)., Methods: We evaluated data of patients who underwent CRC resection between January 1, 2009 and December 31, 2009. Equivocal hepatic lesions of <1 cm in size on preoperative staging CT scans were included in this study. Gadoxetic acid-enhanced liver MRI was subsequently performed in all patients. Hepatic lesions that grew during the follow-up period (≥ 3 years) were considered potential metastases., Results: Overall, 121 equivocal hepatic lesions were detected on preoperative staging CT in 65 out of 494 patients (13.2 %) who underwent colorectal surgery. Based on subsequent MRI, 11 lesions were classified as definitive metastatic lesions and 100 were classified as definitive benign lesions, including simple cysts or hemangiomas. Findings in the other 10 lesions were still inconclusive even after examining CT and MRI. Of the 11 lesions that were classified as metastatic by MRI and were resected, 10 were pathologically confirmed as metastases and one lesion was a pathologically benign nodule. All 100 benign lesions were stable on follow-up imaging and were classified as benign. Of the 10 equivocal lesions, 6 increased in size during the follow up, suggesting they were early metastases, while 4 were stable. The sensitivity and specificity for detecting liver metastases by gadoxetic acid-enhanced MRI of small equivocal hepatic lesions found by CT were 100 % (16/16) and 95.2 % (100/105), respectively, if MRI was equivocal or indicated definite metastasis. The negative predictive value was 100 % (100/100)., Conclusion: Gadoxetic acid-enhanced MRI is a useful diagnostic tool for assessing equivocal hepatic lesions on preoperative CT of CRC patients that allows increased diagnostic accuracy and detection of additional colorectal liver metastasis lesions.

A 20-year-old female patient presented with two masses located in the left liver. In this patient, a computed tomography (CT) scan revealed a hypodense mass and a second well-defined mass with a calcified nodule in the left hepatic lobe. No enhancements were apparent in or around the masses. A laparotomy was performed due to the patient's symptoms, namely, the atypical CT findings and a risk of rupture of the subcapsular lesion. The operation revealed two masses in the left hepatic lobe and a left liver resection was subsequently performed. One of the masses involved segment III and the other mass was located in segment IV. The histopathologic findings supported a diagnosis of collagenous nodule mixed simple cyst and hemangioma. A diagnosis of collagenous nodule mixed simple hepatic cyst is extremely rare and radiologically mimics a teratoma, hepatolithiasis, parasitic cyst, or hemangioma. Although hepatic hemangiomas are the most common benign tumors found in the liver, the present case showed atypical radiographic features.

In 150 patients, 153 hepatic lesions (39 metastases, 27 hemangiomas, 26 hepatocellular carcinomas, 25 cysts, 15 adenomas, 8 focal nodular hyperplasias, 5 abscesses, 4 hamartomas, and 4 cholangiocarcinomas) were evaluated during a 24-month period. Apparent diffusion coefficient (ADC) values of benign lesions (1.994×10(-3) mm(2) s(-1)) were significantly higher than ADC values of malignant lesions (1.070×10(-3) mm(2) s(-1)). Mean ADC value for solid benign lesions (1.143×10(-3) mm(2) s(-1)±0.214×10(-3) mm(2) s(-1)) was not significantly different from malignant lesions. ADC values did not allow differentiating malignant from benign solid lesions (area under the curve=0.61). ADC cutoff value threshold of 1.6×10(-3) mm(2) s(-1) yielded higher accuracy for differentiating benign from malignant lesions., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Different imaging modalities including ultrasonography, computed tomography (CT), and MR imaging may be used in the liver depending on the clinical situation. The ability of dedicated contrast-enhanced liver MR imaging or CT to definitively characterize lesions as benign is crucial in avoiding unnecessary biopsy. Liver imaging surveillance in patients with cirrhosis may allow for detection of hepatocellular carcinoma at an earlier stage, and therefore may improve outcome. This article reviews the different imaging modalities used to evaluate the liver and focal benign and malignant hepatic lesions, and the basic surveillance strategy for patients at increased risk for hepatocellular carcinoma., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Clinical Issue: Cystic liver lesions incorporate a broad heterogeneous group of mostly benign but also malignant abnormalities. The radiological aim is the non-invasive diagnosis with the use of different imaging modalities to determine the type of lesion., Standard Radiological Methods: The common generally asymptomatic incidental findings of cystic lesions on ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) must be classified on the basis of specific imaging features. Such a differentiation is essential because the clinical consequences and the appropriate therapy can vary depending on the underlying pathology. Due to the morphological overlap of many cystic lesions, conventional radiological methods are often insufficient., Methodical Innovations: The huge advances in cross-sectional imaging (multidetector CT, MRI with special sequences and different contrast agents and MR cholangiopancreatography) in combination with the clinical history usually enable a non-invasive diagnosis. Pathognomonic morphological and hemodynamic lesion features, as well as a knowledge of the pathomechanisms, help to differentiate this broad spectrum of entities., Achievements: In this article the different entities of cystic liver lesions, together with the appropriate diagnostic method for detection and distinction and including their strengths and limitations, are demonstrated., Practical Recommendations: A well-founded knowledge about the development of various cystic liver lesions and the suitable choice of imaging method facilitate a non-invasive diagnosis.

Background: Diffusion-weighted (DW) imaging is commonly used to distinguish between benign and malignant liver lesions., Purpose: To prospectively evaluate the true molecular-diffusion coefficient (D), perfusion-related diffusion coefficient (D*), perfusion fraction (f), and ADC of focal hepatic lesions using a free-breathing intravoxel incoherent motion (IVIM) DW sequence, and to determine if these parameters are useful for characterizing focal hepatic lesions., Material and Methods: One hundred and twenty hepatic lesions (34 metastases, 32 hepatocellular carcinoma [HCC], 33 hemangiomas, and 21 liver cysts) in 74 patients were examined. Mean D, D*, f, and ADC values of hepatic lesions were compared among pathologies. ROC curve analyses were performed to assess the performances of D, D*, f, and ADC values for the characterization of liver lesions as benign or malignant., Results: The mean D and ADC values of benign lesions were greater than those of malignant lesions (P < 0.001). Although the mean D and ADC values of liver cysts were greater than those of hemangiomas (P < 0.001), and these values were not significantly different between metastases and HCCs (P = 0.99). Area under the ROC curve for ADC values (0.98) was significantly greater (P = 0.048) than that for D values (0.96) for the differentiation of benign and malignant lesions. Sensitivity and specificity for the detection of malignant lesion were 89% and 98%, respectively, when an ADC cut-off value of 1.40 was applied., Conclusion: D and ADC values have more potential for characterizing focal hepatic lesions than D* or f values, and for the differentiation of malignancy and benignity., (© The Foundation Acta Radiologica 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

Focal liver lesions (FLL) have been a common reason for consultation faced by gastroenterologists and hepatologists. The increasing and widespread use of imaging studies has led to an increase in detection of incidental FLL. It is important to consider not only malignant liver lesions, but also benign solid and cystic liver lesions such as hemangioma, focal nodular hyperplasia, hepatocellular adenoma, and hepatic cysts, in the differential diagnosis. In this ACG practice guideline, the authors provide an evidence-based approach to the diagnosis and management of FLL.

Background: Although diffusion-weighted magnetic resonance imaging imaging (DW-MRI) is commonly used to characterize hepatic lesions, the literature is sparse about the use of MR diffusion tensor imaging (DTI) in this regard. By using DTI, one is able to obtain not only apparent diffusion coefficients (ADCs) but also fractional anisotropy (Fa) values., Purpose: To evaluate DTI using ADC and Fa values in the imaging of hepatic cysts, hemangiomas, and metastases., Material and Methods: Sixty-six patients with 77 lesions were examined with DTI. There were 32 metastases, 13 cysts, and 32 hemangiomas. Two radiologists performed ADC and Fa measurements. Inter-observer agreement was evaluated using Bland-Altman plots. ADCs and Fa values were correlated using Pearson correlation. The differences were compared using ANOVA and Tukey tests. A ROC analysis was applied; sensitivities and specificities were calculated., Results: The inter-observer agreement was very good. The correlation between ADC and Fa was negative, weak, and significant (r = -0.36). The mean ADC value of cysts (3.30 ± 0.8 × 10(-3) mm(2)/s) was significantly higher than that of hemangiomas (2.23 ± 0.5 × 10(-3) mm(2)/s) and metastases (1.62 ± 0.4 × 10(-3) mm(2)/s). The mean Fa value of cysts (0.2 ± 0.05) was significantly lower than hemangiomas (0.37 ± 0.1) and metastases (0.46 ± 0.1). The Az values for discriminating metastases from benign hepatic lesions for ADC and Fa value were 0.885 and 0.731, respectively. The sensitivity and specificity of ADC and Fa were 87.5% and 84.4%, and 78.1% and 57.8%, respectively. The Az value for discriminating cysts from hemangiomas for Fa was 0.96. The sensitivity and specificity were 90.6% and 92.3%, respectively., Conclusion: Fa values may play a supportive role in the imaging of liver lesions. Whereas metastases tend to have low ADCs and high Fa values, cysts have high ADCs and low Fa values and hemangiomas have high ADCs and high Fa values., (© The Foundation Acta Radiologica 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

Introduction: Large simple liver cysts often tend to be symptomatic with pain being the most common symptom., Material and Methods: This was a retrospective study of patients who had intended laparoscopic surgery for liver cysts between December 2007 and December 2012 at a single institution., Results: A total of 31 patients (27 women, four men) had surgery. The median age was 61 years (range 27-81 years). The diagnosis was based on the findings at computed tomography (CT) in 15 patients (49%), at ultrasonography in 11 (35%), at both CT and ultrasound in four (13%) and at magnetic resonance imaging (MRI) in one (3%). Indication for surgery was upper abdominal pain (n = 27) and abdominal discomfort (n = 4). The laparoscopic approach was successful in 29 patients (94%). The two conversions to open surgery were necessary due to peritoneal adherences. The median post-operative hospital stay was one day (range 1-14 days). Histological evaluation revealed 29 non-neoplastic cysts (94%) and two cyst adenomas (6%). Two patients had minor post-operative complications, but none needed re-operation. There was no 30-day mortality. The median follow-up time was 28 months (range 1-60 months). At follow-up, 26 patients (84%) were symptom-free. Of the five patients with re-occurrence of symptoms, three had a re-operation. The remaining two refrained from new surgery., Conclusion: Laparoscopic marsupialisation of simple liver cysts has a high success rate in terms of pain relief, and it is a safe procedure with a short post-operative hospital stay., Funding: not relevant., Trial Registration: Study reported to Danish Data Protection Agency via Region of Southern Denmark (case no. 13/8542).

Endometrial cysts within the liver are rare but can present as diagnostic challenges on small biopsies or frozen sections and may mimic mucinous cystic neoplasms (MCN) of the liver. Five cases of endometrial cysts and 6 cases of MCNs within the liver were collected. The clinicopathological, imaging, and immunohistochemical features were systematically reviewed and compared. The average size of the endometrial cysts was 8.3 cm. Four patients had a prior pelvic operation and coexisting endometriosis at other sites. All 5 cases of endometrial cysts had positive ER staining within both the epithelium and the stroma. PR was also positive in both epithelial and stromal cells in 4 cases. Four cases had additional immunostains performed, which all showed cytokeratin 19 and cytokeratin 7 positivity (only in epithelium) and CD10 positivity (only in stroma). α-Inhibin and calretinin were negative for both the epithelium and the stroma in all 4 cases. All 6 MCN cases (mean size, 11.1 cm) had positive ER, PR, and α-inhibin staining only in the stroma. ER and PR were positive in both the epithelium and stromal cells in endometrial cysts, whereas they were positive only in the stromal cells of MCNs. The stromal cells were CD10 positive and α-inhibin negative in endometrial cysts as opposed to the opposite staining pattern in MCNs. Awareness of this distinct staining pattern and the possibility of endometrial cysts in the liver can lead to accurate diagnoses and appropriate treatment modalities., (Copyright © 2014 Elsevier Inc. All rights reserved.)

A 59-year-old patient was admitted to hospital with recurrent flush symptoms and pathologically elevated 5-hydroxyindoleacetic acid (5-HIAA) levels in urine. A known cystic lesion of the liver which had been followed for years by ultrasound examinations and was regarded as a bland hepatic cyst was identified as a metastasis of a neuroendocrine neoplasm of the ileum. In two sequential surgical interventions the primary tumor with mesenteric lymph node metastases as well as the cystic liver metastasis could be resected. After surgical treatment an R1 situation at the mesenteric site and suspicious para-aortic lymph nodes remained. The long established treatment of factor-V Leiden mutation by anticoagulation with phenprocoumon was supplemented by deep subcutaneous injection of lanreotide autogel every 4 weeks. Currently, there is no evidence for progressive disease and the patient is without clinical signs of a carcinoid syndrome.

Biliary cystadenoma (BCA) is a rare hepatic neoplasm. Although considered a benign cystic tumor of the liver, BCA has a high risk of recurrence with incomplete excision and a potential risk for malignant degeneration. Correct diagnosis and complete tumor excision with negative margins are the mainstay of treatment. Unfortunately, due to the lack of presenting symptoms, and normal laboratory results in most patients, BCA is hard to distinguish from other cystic lesions of the liver such as biliary cystadenocarcinoma, hepatic cyst, hydatid cyst, Caroli disease, undifferentiated sarcoma, intraductal papillary mucinous tumor, and hepatocellular carcinoma. Ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) may be necessary. They demonstrate intrahepatic cystic lesions with features such as mural nodules, varying wall thickness, papillary projections, and internal septations. Nevertheless, surgery is still the only means of accurate diagnosis. Definitive diagnosis requires histological examination following formal resection. We describe a 57-year-old woman initially diagnosed with polycystic liver who was subsequently diagnosed with giant intrahepatic BCA in the left hepatic lobe. This indicates that both US physicians and hepatobiliary specialists should attach importance to hepatic cysts, and CT or MRI should be performed for further examination when a diagnosis of BCA is suspected.

A multilocular cystic hepatic lesion detected at computed tomography (CT) and magnetic resonance (MR) imaging is a common but nonspecific radiologic finding that can cause potential challenges for differential diagnosis. This imaging pattern may be observed in a wide spectrum of common and uncommon neoplastic or nonneoplastic entities. Neoplastic lesions include cystadenoma, cystadenocarcinoma, hepatocellular carcinoma (HCC), metastases, mesenchymal hamartoma, and inflammatory myofibroblastic tumor. Nonneoplastic lesions include hepatic abscess, echinococcal cyst, intrahepatic hematoma, and biloma. The multiple coalescent cysts seen in polycystic liver disease may exhibit an imaging pattern similar to that of a multilocular cystic lesion. Mural nodularity, irregular thickness of the septa, ragged inner surface, and typical enhancement pattern in the solid portion of the lesion are often indicative of malignancy, although multilocular primary or secondary malignant tumors are uncommon. Recognition of the more common necrosis or cystic change of HCC and metastases induced by locoregional or systemic treatment also is important. The nonenhanced cystic component may be composed of different types of fluids (eg, serous, mucinous, proteinaceous, hemorrhagic, bilious, or mixed) or spontaneous or treatment-related necrosis, whereas the septa may be formed by a wide range of tissues depending on the lesion type. An understanding of the CT and MR imaging findings of these lesions and their respective pathologic correlation aids in accurate diagnosis.

Hepatic cysts are increasingly found as a mere coincidence on abdominal imaging techniques, such as ultrasonography (USG), computed tomography (CT) and magnetic resonance imaging (MRI). These cysts often present a diagnostic challenge. Therefore, we performed a review of the recent literature and developed an evidence-based diagnostic algorithm to guide clinicians in characterising these lesions. Simple cysts are the most common cystic liver disease, and diagnosis is based on typical USG characteristics. Serodiagnostic tests and microbubble contrast-enhanced ultrasound (CEUS) are invaluable in differentiating complicated cysts, echinococcosis and cystadenoma/cystadenocarcinoma when USG, CT and MRI show ambiguous findings. Therefore, serodiagnostic tests and CEUS reduce the need for invasive procedures. Polycystic liver disease (PLD) is arbitrarily defined as the presence of > 20 liver cysts and can present as two distinct genetic disorders: autosomal dominant polycystic kidney disease (ADPKD) and autosomal dominant polycystic liver disease (PCLD). Although genetic testing for ADPKD and PCLD is possible, it is rarely performed because it does not affect the therapeutic management of PLD. USG screening of the liver and both kidneys combined with extensive family history taking are the cornerstone of diagnostic decision making in PLD. In conclusion, an amalgamation of these recent advances results in a diagnostic algorithm that facilitates evidence-based clinical decision making.

Background/aims: Mucinous cystic neoplasms (MCN) are rare liver lesions. Radiological features include internal septa or septal thickening. Imaging often fails in the differential diagnosis to non-parasitic liver cysts (NPLC), resulting in inadequate surgery. The aim of the study was to evaluate if both lesions could be differentiated pre-operatively., Methodology: Retrospective study with literature review., Results: Twenty-six patients (22 female, 68±12 years) underwent laparoscopic deroofing for NPLC. Histo-pathological specimens showed 2 MCN (both female) with recurrence rates of 4% (NPLC) and 100% (MCN), and a time-to-recurrence of 3 months. In both cases no radiological features of MCN were seen pre-operatively. Follow-up time was 7 and 12 years with emergence of radiological features of MCN in one case. PubMed search showed 137 hits for “MCN” and 540 hits for “mucinous cystadenoma” and “liver”; 207 studies were reviewed: one prospective, 13 non-systematic reviews, 57 retrospective, 120 case reports and 16 expert opinions. The largest MCN-series included 44 subjects., Conclusions: If MCN shows no characteristic radiological features, thus mimicking NPLC, pre-operative radiological differentiation is impossible. During long time course characteristic radiological morphology of MCN could appear. Early recurrence of a supposed NPLC is suspicious for MCN. Due to the literature review pre-operative imaging is inaccurate for the differential diagnosis and complete surgical excision of MCN is crucial.

Background: Although cystic colorectal metastases are rare (1.8%), they are still a crucial challenge for the surgeon especially in terms of detection and differential diagnosis. Since prognosis after resection is very good (40% 5-year survival), early diagnosis is essential., Case Report: A 55-year-old man was admitted to our hospital with a suspected diagnosis of multiple small liver metastases. He had previously undergone left sided-cholectomy followed by chemotherapy for colonic carcinoma. Computed tomography (CT) revealed multiple small (<15 mm) intrahepatic biliary cysts, suspected for cystic colorectal liver metastases., Conclusion: The diagnosis of cystic colorectal liver metastases is quite difficult and it is mostly based on the last-generation magnetic resonance (MR). In spite of this, we must often rely on histological results for a definitive diagnosis.

The differential diagnosis of a liver mass is large and requires understanding of the clinical and imaging features of liver lesions. A detailed history, physical examination, hepatic biochemical tests, and imaging studies are all essential in making the diagnosis. Decisions regarding specific imaging modalities for diagnoses, the use of liver biopsy, therapeutic options, and appropriate follow-up are all determined by the presentation of the lesion and associated patient characteristics., (Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.)

Objectives: We compared the diagnostic performance of gadoxetic acid-enhanced MRI and 16-slice multidetector CT (MDCT) with respect to their abilities to detect hepatic metastases and differentiate hepatic metastases from hepatic cysts and haemangiomas., Methods: 67 patients with 110 liver metastases (size 0.3-2.5 cm), 33 haemangiomas (size 0.5-1.5 cm) and 17 cysts (size 0.3-1.0 cm) underwent 4-phase MDCT and gadoxetic acid-enhanced MRI, including early dynamic phases, post-contrast T(2) weighted turbo spin echo sequences and 20 min hepatocyte-selective phases. Two observers independently analysed each image in random order. Sensitivity and diagnostic accuracy for lesion detection and differentiation for MDCT and gadoxetic acid-enhanced MRI were calculated using receiver operating characteristic analysis., Results: For both observers, the Az values of gadoxetic acid-enhanced MRI (mean, 0.982 and 0.981) were significantly higher than the Az values of MDCT (mean, 0.839 and 0.892) (p<0.05) for the detection of metastases and for the differentiation of metastases from haemangiomas and cysts. Sensitivities of gadoxetic acid-enhanced MRI with regard to the detection and characterisation of liver metastases (mean, 96.9% and 96.0%) were significantly higher than those of MDCT (mean, 78.7% and 75.0%) (p<0.05)., Conclusion: Gadoxetic acid-enhanced MRI showed higher diagnostic accuracy and sensitivity than did MDCT for the detection of hepatic metastases and for the differentiation between hepatic metastases and hepatic haemangiomas or cysts.

Background: Undifferentiated embryonal sarcoma (UES) of the liver is a rare, highly malignant neoplasm with a poor prognosis occurring almost exclusively in late childhood (6-10 years of age). Only a few cases have been reported in adults, accounting for less than 1% of all primary liver neoplasms., Methods: A 47-year-old woman presented with a palpable mass in the left upper abdomen. Magnetic resonance imaging revealed a 12x10 cm cystic mass with hemorrhage in the left lateral segment of the liver. The initial impression was a hemorrhagic cystic tumor of the liver. The patient underwent a left lateral sectionectomy of the liver. Histopathology and immunohistochemistry helped make a diagnosis of UES., Results: The patient recovered uneventfully and received systemic chemotherapy. Radiologic examination for follow-up revealed a metastatic lesion in the lumbar spine (L5). She was subjected to radiotherapy at the lumbar spine. She survived 48 months., Conclusion: Although hepatic cyst as UES of the liver is difficult to diagnose because of its rarity in adults and lack of specific findings, it should be considered in a differential diagnosis.

Ultrasound contrast agents have gained wide acceptance for the detection and characterization of focal liver lesions. This pictorial essay reviews the growing body of evidence that supports the use of modern ultrasound contrast agents and illustrates the enhancement characteristics of commonly encountered focal liver lesions. Pathologies discussed include metastases, hepatocellular carcinomas, focal nodular hyperplasia, hepatocellular adenomas, hemangiomas, abscesses, complex cysts, and focal fatty deposition., (Copyright © 2011 Wiley Periodicals, Inc.)

A profound knowledge of the various benign focal hepatic lesions and selection of the most suitable radiological examination modality is essential for achieving an accurate characterization of a hepatic lesion and in turn will determine the further patient management. This will avoid unnecessary agitation to both patient and the referring clinician and limits time-consuming, costly and risky biopsies to an absolute minimum. The following article will discuss the typical and atypical appearances of the most frequent and clinically relevant benign focal hepatic lesions with ultrasound, computed tomography and magnetic resonance imaging.

The widespread use of imaging analyses, either routinely or to evaluate symptomatic patients, has increased the detection of liver lesions (tumors and cysts) in otherwise healthy individuals. Although some of these incidentally discovered masses are malignant, most are benign and must be included in the differential diagnosis. The management of benign hepatic tumors ranges from conservative to aggressive, depending on the nature of the lesions. New imaging modalities, increased experience of radiologists, improved definition of radiologic characteristics, and a better understanding of the clinical features of these lesions have increased the accuracy of diagnoses and reduced the need for invasive diagnostic tests. These advances have led to constant adjustments in management approaches to benign hepatic lesions. We review the biologic and clinical features of some common hepatic lesions, to guide diagnosis and management strategies., (Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Objective: The purpose of this study was to evaluate the use of diffusion-weighted imaging (DWI) for the detection and characterisation of focal hepatic lesions compared with the use of T(2) weighted imaging., Method: 45 patients with 97 hepatic lesions (51 malignant lesions and 46 benign lesions) were included in this retrospective study. Malignant hepatic lesions included 12 hepatocellular carcinomas, 26 metastases and 13 intrahepatic cholangiocarcinomas. Benign hepatic lesions included 19 haemangiomas and 27 cysts. The MRI protocol for the upper abdomen included T(2) weighted images, in- and opposed-phase T(1) weighted images and dynamic T(1) weighted images. Breath-hold fat-suppressed single-shot echo planar DWI was performed with the following parameters: 1338/66; b factors, 0, 50 and 800 s mm(-2). Two independent observers reviewed the T(2) weighted images and the DWI to detect and to characterise the hepatic lesions., Results: For detection of malignant hepatic lesions, the use of DWI showed a significantly higher detection rate than the use of T(2) weighted images (p<0.05). However, there was no significant difference between the use of DWI and T(2) weighted images for benign hepatic lesions. For the differentiation between malignant and benign hepatic lesions, there was no significant difference in sensitivity, specificity and accuracy between the use of T(2) weighted images and the use of DWI., Conclusion: The use of DWI was better for the detection of malignant hepatic lesions than the use of T(2) weighted images. However, for detection of benign hepatic lesions and characterisation of hepatic lesions, the use of DWI was equivalent to the use of T(2) weighted images.

Background/purpose: Although hepatic hemangiomas and cysts display very high signal intensities on conventional T2 images, their appearances are quite distinct using magnetic resonance hydrography (MRH). We examined the feasibility of using MRH in distinguishing hepatic cysts from hemangiomas., Methods: We recruited 97 patients with hepatic hemangiomas and 65 with hepatic cysts. All patients underwent magnetic resonance imaging (including two-dimensional multiple slice MRH, TR/TE: 8000/800) and the results were reviewed independently by two radiologists. The signal intensities of the lesions were measured. For each lesion, the variation in signal to noise ratio between MRH and the fat-saturated T2-weighted images was calculated, and the results were validated using a receiver operating characteristic curve., Results: There was a significant difference between the signal to noise ratio of hepatic hemangiomas and cysts using MRH (p < 0.001). This difference could be identified by visual inspection. The receiver operating characteristic curve revealed that the ideal cut-off value for the signal intensity reduction ratio between hepatic cysts and hemangiomas was -0.1. Using this ratio, the derived sensitivity was 95.4%, specificity 99.0%, and accuracy 99.7%., Conclusion: Hepatic hemangiomas and cysts have significantly different signal intensities on non-contrast two-dimensional multiple-slice MRH. This approach uses a non-invasive, reliable, and accurate imaging technique to differentiate the two diagnoses., (Copyright © 2011 Formosan Medical Association & Elsevier. Published by Elsevier B.V. All rights reserved.)

During recent years, we have experienced an increased detection of previously unsuspected liver masses in otherwise asymptomatic patients owing to the widespread application of imaging techniques. Regardless of the malignant or cystic tissues, a remarkable percentage of these masses are represented by benign solid neoplasms. Treatment of benign liver tumors still represents a major concern in the hepatic surgery field. Indications for surgery have remained unchanged for many years, but the laparoscopic approach could determine in some cases a broadening of indications, which may result in overtreatment. In this article, the main surgical indication for hepatic hemangioma, focal nodular hyperplasia and hepatocellular adenoma are discussed with regard to the most recent advancements in literature. In addition, a separate section deals with the role of laparoscopy in the treatment of benign liver neoplasms.

Cystic lesions of the liver are common. Most of these represent benign simple cysts that generally require no intervention. The diagnosis of simple hepatic cysts is straightforward in the face of typical radiographic findings; however, diagnostic uncertainty, based solely on radiographic criteria alone, is not an uncommon clinical dilemma. In this report, we present a case of a 47 old woman with a cystic liver lesion and acute epigastric pain. The patient had no previous history of oral contraceptive assumption or liver disease. A tender mass was palpable on the upper right quadrant of the abdomen. The abdominal ultrasound (US) showed a cystic lesion with a possible hemorrhagic component on right liver lobe. Abdominal computed tomography (CT) and magnetic resonance (MR) revealed a complex cystic lesion with possible intracystic hemorrhage. The patient was submitted to operation and resection; the final histologic diagnosis revealed a primary undifferentiated embryonal sarcoma of the liver. She relapsed 24 months after a new hepatic resection and chemo-embolization, she is alive at 29 months after first surgery.

There is a wide range of benign liver tumors that behave in very different ways and require a management strategy specifically tailored to each. The most common benign solid liver tumor is hemangioma followed by focal nodular hyperplasia; the most common cystic tumor is the simple cyst. Most of these tumors are asymptomatic and are discovered as incidental findings on imaging tests performed for other reasons. Usually, no treatment or follow-up is required. The differential diagnosis with malignant liver tumors is sometimes difficult. This difficulty, together with the presence of symptoms or complications, is the main reason for surgical resection.