A 6-Week-Old Boy With Irritability and Abdominal Distension

A 6-week-old boy is brought to the hospital for fussiness and abdominal distension. He was febrile on presentation and was admitted to the hospital for further evaluation. On subsequent examinations, he continued to demonstrate abdominal distension and tenderness to palpation. Ultrasonography of the abdomen was performed and revealed a heterogeneous liver mass. With further diagnostics, a diagnosis was made and treatment initiated, with the infant experiencing resolution of his symptoms. Our panel of experts first discuss the management of an infant with abdominal distension, then discuss the evaluation of a liver mass in an infant, including oncologic, vascular, and infectious etiologies.

Imaging of Invasive Fungal Infections- The Role of PET/CT

Over the last decades, the population at risk for invasive fungal disease (IFD) has increased because of medical therapy advances and diseases compromising patients' immune systems. The high morbidity and mortality associated with invasive fungal disease in the immunocompromised present the challenge of early diagnosis of the IFD and the need to closely monitor the infection during treatment. The definitive diagnosis of invasive fungal disease based on culture or histopathological methods often has reduced diagnostic accuracy in the immunocompromised and may be very invasive. Less invasive and indirect evidence of the fungal infection by serology and imaging has been used for the early diagnosis of fungal infection before definitive results are available or when the definitive methods of diagnosis are suboptimal. Imaging in invasive fungal disease is a non-invasive biomarker that helps in the early diagnosis of invasive fungal disease but helps follow-up the infection during treatment. Different imaging modalities are used in the workup to evaluate fungal disease. The different imaging modalities have advantages and disadvantages at different sites in the body and may complement each other in the management of IFD. Positron emission tomography integrated with computed tomography with [18F]Fluorodeoxyglucose (FDG PET/CT) has helped manage IFD. The combined functional data from PET and anatomical data from the CT from almost the whole body allows noninvasive evaluation of IFD and provides a semiquantitative means of assessing therapy. FDG PET/CT adds value to anatomic-based only imaging modalities. The nonspecificity of FDG uptake has led to the evaluation of other tracers in the assessment of IFD. However, these are mainly still at the preclinical level and are yet to be translated to humans. FDG PET/CT remains the most widely evaluated radionuclide-based imaging modality in IFD management. The limitations of FDG PET/CT must be well understood, and more extensive prospective studies in uniform populations are needed to validate its role in the management of IFD that can be international guidelines.

Undifferentiated embryonal sarcoma of liver with macroaneurysms and arteriovenous shunt

Undifferentiated embryonal sarcoma (UES) is an uncommon primary hepatic tumour of childhood. The mass usually shows paradoxical features of being cystic on CT and solid on ultrasound. These lesions are usually hypovascular. Very rarely they may present as hypervascular liver masses with macroaneurysms and arteriovenous (AV) shunt, with only less than six cases reported in literature. We report a case of an 11-year-old child who presented with progressive abdominal distention, and CT revealed a large exophytic hypervascular mass of liver with multiple macroaneurysms, pooling of contrast and a high-flow AV shunt. Histopathology, along with immunohistochemistry, revealed the mass to be UES. The child underwent neoadjuvant chemotherapy followed by successful surgery. The prognosis of this tumour depends on prompt diagnosis and early intervention. We present this case to highlight the atypical presentation of UES, which will encourage radiologists to keep this differential in relevant clinical settings.

Paediatric gastrointestinal and hepatobiliary radiology: why do we need subspecialists, and what is new?

We present the case for subspecialisation in paediatric gastrointestinal and hepato-pancreatico-biliary radiology. We frame the discussion around a number of questions: What is different about the paediatric patient and paediatric gastrointestinal system? What does the radiologist need to do differently? And finally, what can be translated from these subspecialty areas into everyday practice? We cover conditions that the sub-specialist might encounter, focusing on entities such as inflammatory bowel disease and hepatic vascular anomalies. We also highlight novel imaging techniques that are a focus of research in the subspecialties, including contrast-enhanced ultrasound, MRI motility, magnetisation transfer factor, and magnetic resonance elastography.

The utility of abdominal ultrasonography in the diagnosis of fungal infections in children: a narrative review

In paediatric patients, ultrasonography is one of the preferred medical imaging modalities due to the lack of ionising radiation. Abdominal ultrasonography can be a useful tool in diagnosing cases of fungal infections but may introduce some risks for further infection in vulnerable patients or cause anxiety and discomfort. The aim of this narrative review is to analyse the utility of abdominal ultrasonography in diagnosing fungal infections in children in terms of its positive hit rates and utility in typical use. Text words and indexed terms related to 'fungal infection and ultrasonography' and 'children' were searched on MEDLINE, EMBASE, Cochrane Library and Scopus. Paediatric oncology patients, neonates and generally immunocompromised children were found to be at-risk groups with increasing susceptibility to risk factors for contracting fungal infections. Abdominal ultrasonography was found to aid in the diagnosis of fungal infection in many cases, but not all patients with the identified risk factors were diagnosed with fungal infections and not all patients diagnosed with fungal infections had identified risk factors. Ultrasonography was found to be overutilised and the current decision process in requesting abdominal ultrasonography in diagnosing fungal infection should be revised. Further study into an effective criterion in requesting abdominal ultrasonography is suggested to reduce the overutilisation of ultrasonography, thus reducing risk of infection and discomfort while also saving time and money.

Focal nodular hyperplasia masquerading as malignancy in an infant with elevated alpha-fetoprotein: A case report with literature review

We describe a unique case of focal nodular hyperplasia (FNH) in a 6-month-old-girl with elevated alpha-fetoprotein (AFP). Given the patient's age and elevated AFP, a diagnosis of hepatoblastoma was presumed. However, the histopathologic assessment of the lesion was typical for focal nodular hyperplasia. This was further corroborated using hepatobiliary contrast agent to exclude the possibility of a collision or a composite liver tumor.

Magnetic resonance imaging features of common focal liver lesions in children

Magnetic resonance imaging (MRI) is commonly used to characterize focal liver masses in the pediatric population. MRI is the preferred modality because of its superior contrast resolution and utility for obtaining functional sequences such as diffusion-weighted imaging (DWI). MR exams performed with a hepatocyte-specific gadolinium-based contrast agent can characterize focal liver lesions, which helps in differentiating a common benign entity such as focal nodular hyperplasia from other liver pathology when the background liver is normal. The most common benign focal lesion is a hemangioma, and metastases followed by hepatoblastoma are the most common malignant lesions. This article can help radiologists become familiar with the pre- and post-contrast imaging features of common pediatric liver masses.

Solid Liver Lesions in an Infant With Neonatal Cholestasis: Is it Always Malignant?

In this report we describe a patient with neonatal cholestasis who was found to have a liver lesion with suspicious imaging features, although ultimately it was histologically proved to be a pseudotumor. We discuss the characteristic features and imaging findings of macroregenerative nodules of the liver.

Huge focal nodular hyperplasia presenting in a 6-year-old child: A case presentation

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FNH is a benign lesion of the liver which is rare in children.

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We report the case of a 6-year-old child (male) with a huge FNH which size is more than 10 cm. This could be the biggest FNH among all children’s FNH cases ever reported.

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When pediatric FNH patients accord with (1) clinical symptoms; (2) indefinite diagnosis or hepatitis B virus carriage; (3) tumor size >5 cm, surgical treatment could be considered.

Introduction

Focal nodular hyperplasia (FNH) is a benign lesion of the liver which is usually found in healthy adults, however, FNH is rare in children, and comprises only 2% of all pediatric liver tumors. Herein, we report the case of a 6-year-old child (male) with a huge FNH which size is more than 10 cm. This could be the biggest FNH among all children’s FNH cases ever reported.

Case presentation

A 6-year-old boy was found a hepatic space-occupying lesion two years ago. As the time went by, the lesion became bigger gradually. The last CT examination showed the size of the tumor to be 10.5 × 9.9 cm in the right hepatic lobe. This child underwent surgical resection of the tumor which was confirmed as FNH (11 × 8 × 7 cm) by pathology.

Conclusion

FNH is a benign lesion of the liver, and it is characterized by hepatocyte hyperplasia and a central stellate scar. It is uncommon for FNH to be diagnosed in children. Such huge FNH (about 11 cm) is extremely rare. Surgical operation may be the effective method to cure huge FNH.

MRI of paediatric liver tumours: How we review and report

Liver tumours are fortunately rare in children. Benign tumours such as haemangiomas and cystic mesenchymal hamartomas are typically seen in infancy, often before 6 months of age. After that age, malignant hepatic tumours increase in frequency. The differentiation of a malignant from benign lesion on imaging can often negate the need for biopsy. Ultrasound is currently the main screening tool for suspected liver pathology, and is ideally suited for evaluation of hepatic lesions in children due to their generally small size. With increasing research, public awareness and parental anxiety regarding radiation dosage from CT imaging, MRI is now unquestionably the modality of choice for further characterisation of hepatic mass lesions.

Nevertheless the cost, length of imaging time and perceived complexity of a paediatric liver MR study can be intimidating to the general radiologist and referring clinician. This article outlines standard MR sequences utilised, reasons for their utilisation, types of mixed hepatocyte specific/extracellular contrast agents employed and imaging features that aid the interpretation of paediatric liver lesions. The two commonest paediatric liver malignancies, namely hepatoblastoma and hepatocellular carcinoma are described. Differentiation of primary hepatic malignancies with metastatic disease and mimickers of malignancy such as focal nodular hyperplasia (FNH) and hepatic adenomas are also featured in this review..

Imaging should aim to clarify the presence of a lesion, the likelihood of malignancy and potential for complete surgical resection. Reviewing and reporting the studies should address these issues in a systematic fashion whilst also commenting upon background liver parenchymal appearances. Clinical information and adequate patient preparation prior to MR imaging studies help enhance the diagnostic yield.

Magnetic resonance imaging of primary pediatric liver tumors

Although primary hepatic neoplasms are less common than other intra-abdominal tumors in children, these neoplasms are a significant source of morbidity and mortality in the pediatric population. MRI is increasingly relied upon in the diagnostic evaluation of these lesions, both before and after treatment, and familiarity with the MRI findings associated with these neoplasms is a must for pediatric radiologists. Advances in MRI technology, particularly the advent of hepatocyte-specific gadolinium-based MRI contrast agents, have allowed for accurate characterization of several types of hepatic neoplasms on the basis of imaging appearance. In this review, we provide an overview of the approach to imaging hepatic neoplasms in children using MRI, including a sample imaging protocol. We also discuss the relevant clinical features and MRI findings of the most clinically relevant entities, including their appearance on post-contrast imaging using hepatocyte-specific gadolinium-based MRI contrast agents.

Hepatoblastoma Associated with Trisomy 18

Very few reports exist in the literature regarding a possible association between trisomy 18 patients and the incidence of hepatoblastoma. Fewer reports exist on patients with multifocal hepatoblastoma. We reviewed our institutional database for the past 10 years and found three cases with this possible association to the tumor.

Transarterial embolisation of a large focal nodular hyperplasia, using microspheres, in a paediatric patient

Benign liver tumours are uncommon in children, haemangiomas being the most frequent. Focal nodular hyperplasia (FNH) represents about 2% of paediatric liver tumours. In children, as in adults, a conservative approach is generally recommended. However, large lesions (greater than 5 cm) are more frequent in the paediatric age group, and in these cases, as well as in growing lesions, surgical removal may be advised. Transarterial embolisation (TAE) has been a successful alternative option described in older patients, especially in cases where surgical removal is not possible. This minimally invasive procedure may also become an option in the paediatric group. The authors report the case of a boy with a large FNH treated with TAE using microspheres.

Focal nodular hyperplasia in children: an institutional experience with review of the literature

BACKGROUND

Focal nodular hyperplasia (FNH) is uncommonly diagnosed in pediatric patients and may be difficult to distinguish from a malignancy. We present a review of all children with a tissue diagnosis of FNH at our institution, describe the diagnostic modalities, and provide recommendations for diagnosis and follow-up based on our experience and review of the literature.

METHODS

A retrospective review of children <18years of age diagnosed with FNH at a single institution was performed from 2000 to 2013.

RESULTS

Twelve patients were identified with a tissue diagnosis of FNH. Two patients required surgical resection of their lesion owing to concern for malignancy. Ten patients were managed expectantly with imaging surveillance after biopsy confirmed a diagnosis of FNH. All patients who underwent MRI had very typical findings including hypointensity on T1 weighted sequences, hyperintensity on T2, and homogenous uptake of contrast on the arterial phase. On follow-up all patients had either a stable lesion or reduction in size.

CONCLUSIONS

Focal nodular hyperplasia presents typically in children with liver disease, have undergone chemotherapy, and adolescent females. Young children, particularly <5years of age, without underlying liver disease or history of chemotherapy can pose a diagnostic dilemma. In this unique subgroup of children with FNH, MRI and/or needle biopsy should be adequate diagnostic modalities for these lesions.

The impact of hepatocyte phase imaging from infancy to young adulthood in patients with a known or suspected liver lesion

OBJECTIVE

Hepatocyte-specific contrast agents are used to help characterize liver lesions. However, there are no studies evaluating the utility of these agents in detecting or diagnosing pediatric liver lesions. The purpose of this study is to assess the impact of the hepatocyte phase of imaging on lesion detection, tumor staging and diagnostic confidence.

MATERIALS AND METHODS

All patients undergoing an MRI between September 2010 and August 2012 using gadoxetate disodium as the contrast agent were included in this study. Each exam was duplicated so that one copy contained all sequences, including the hepatocyte phase of imaging, and the other copy contained all sequences except the hepatocyte phase of imaging. One reviewer evaluated all exams in a blinded, random fashion. Data tracked included imaging diagnosis, confidence in diagnosis, number of lesions and PRETEXT grade. The imaging diagnosis was compared to histopathology, when available. Data were analyzed for the study population as well as the subset of patients diagnosed with focal nodular hyperplasia (FNH).

RESULTS

There were 112 patients (56 male; mean age: 9.25 years) included in this study. A total of 33 patients had a malignant tumor and the remainder had either a benign lesion or no lesion. The addition of the hepatocyte phase of imaging significantly improved the diagnostic confidence for all patients (P < 0.0001) as well as specifically for patients diagnosed with FNH (P = 0.003). In nearly a quarter of patients, the hepatocyte phase of imaging allowed the reviewer to detect additional lesions (P = 0.005). In the patients with a malignant tumor, the addition of the hepatocyte phase of imaging changed the PRETEXT grade in 7/30 patients although the results were not significant (P = 0.161).

CONCLUSION

The addition of the hepatocyte phase of imaging helps to improve lesion detection and increase the diagnostic confidence for all liver tumors, as well as for FNH in particular.

The impact of share wave elastography in differentiation of hepatic hemangioma from malignant liver tumors in pediatric population

OBJECTIVE

In children it is crucial to differentiate malignant liver tumors from the most common benign tumor, hepatic hemangiomas since the treatment strategies are quite different. We aimed to evaluate the efficiency of shear wave elastography (SWE) technique in differentiation of malignant hepatic tumors and hepatic hemangiomas.

METHODS

Twenty patients with hepatic tumor were included in our study. Two radiologists performed SWE for 13 patients with malignant hepatic tumors including hepatoblastoma (n=7), hepatocellular carcinoma (n=3), metastasis (n=2), embryonal sarcoma (n=1) and 7 patients with hepatic hemangioma. All of our patients were between the age of 1 and 192 months (mean age: 56.88 months). Receiver operating characteristic analysis was achieved to evaluate the diagnostic accuracy of SWE and to determine the optimal cut-off value in differentiation hepatic hemangioma from malignant hepatic tumors.

RESULTS

The mean SWE values (in kPa) for the first observer were 46.94 (13.8-145) and 22.38 (6.6-49.6) and those for the second observer were 57.91 (11-237) and 23.87 (6.4-57.5), respectively for malignant hepatic tumors and hepatic hemangiomas. The SWE values of malignant hepatic tumors were significantly higher than those of hepatic hemangioma (p=0.02). The inter-observer agreement was almost perfect (0.81). The area under the receiver operating characteristic curve of SWE for differentiating the hepatic hemangioma from malignant hepatic tumors was 0.77 with a sensitivity of 72.7% and a specificity of 66.7% at a cutoff value of 23.62 with 95% confidence interval.

CONCLUSION

Shear wave elastography can be helpful in differentiation of malignant hepatic tumors and hepatic hemangioma.

Paediatric ultrasonography of the liver, hepatobiliary tract and pancreas

In the field of paediatric radiology ultrasonography (US) is the most versatile imaging tool available. Children in general, by virtue of their body composition, are excellent candidates for US exams in whom abdominal anatomy and pathology can be visualised in great detail. The fact that during the US study a clinical history can be obtained strongly adds to the value of the US exam. This does require investment in time and expertise and ideally a paediatric radiologist performing the exam. In this review the role of ultrasonography (US) of the liver, biliary tract and pancreas in children is discussed.

Hepatobiliary cystadenoma: a rare pediatric tumor

Hepatobiliary cystadenoma is a rare hepatic neoplasm that has been reported only 10 times in the pediatric population. Although considered a benign cystic tumor of the liver, hepatobiliary cystadenoma has a high risk of recurrence with incomplete excision and a potential risk for malignant degeneration. Complete tumor excision with negative margins is the mainstay in treatment. Unfortunately, due to the paucity of cases and its vague presentation, hepatobiliary cystadenoma is rarely diagnosed preoperatively. Therefore, in patients with hepatic cystic masses without a clear diagnosis, total resection of the lesion with negative margins is indicated to adequately evaluate for malignant potential and limit the risk of recurrence. We describe a 2-year-old girl with an asymptomatic abdominal mass that was found to be hepatobiliary cystadenoma. In addition, the pathogenic, histopathologic and clinical features of hepatobiliary cystadenoma are reviewed.

Hepatobiliary cystadenoma: a rare pediatric tumor

Hepatobiliary cystadenoma is a rare hepatic neoplasm that has been reported only 10 times in the pediatric population. Although considered a benign cystic tumor of the liver, hepatobiliary cystadenoma has a high risk of recurrence with incomplete excision and a potential risk for malignant degeneration. Complete tumor excision with negative margins is the mainstay in treatment. Unfortunately, due to the paucity of cases and its vague presentation, hepatobiliary cystadenoma is rarely diagnosed preoperatively. Therefore, in patients with hepatic cystic masses without a clear diagnosis, total resection of the lesion with negative margins is indicated to adequately evaluate for malignant potential and limit the risk of recurrence. We describe a 2-year-old girl with an asymptomatic abdominal mass that was found to be hepatobiliary cystadenoma. In addition, the pathogenic, histopathologic and clinical features of hepatobiliary cystadenoma are reviewed.