Widening spectrum of liver angiosarcoma in children

"Update on pediatric primary liver tumors"

Liver masses are common in children, however primary malignant neoplasms are rare, representing only 1% of all pediatric cancers. Hepatocellular neoplasms are the most common primary liver malignancies and hepatoblastoma (HB) is the most frequently diagnosed. The incidence of HB, which is increasing, is approximately of 2 cases per million in the United States, followed by hepatocellular carcinoma (HCC). Pediatric primary liver tumors of mesenchymal origin are less common, except for benign vascular tumors (hemangiomas). Malignant mesenchymal neoplasms represent approximately 10-15% of all, the most common being embryonal sarcoma and malignant rhabdoid tumor. Malignant vascular tumors are rare, but epithelioid hemangioendothelioma (EHE) and angiosarcoma can be seen in children. The development and adoption of consensus diagnostic, therapeutic and risk-stratifying approaches for pediatric patients with malignant liver tumors has been historically challenged by their rarity and by their diverse clinical and histological appearance. On-going collaborative efforts of international consortia including the Children's Oncology Group (COG) in North America, the German Society of Paediatric Oncology and Haematology (GPOH), the Societe Internationale d' Oncologie Pediatrique Liver Tumor Study Group (SIOPEL) in Europe and the Japanese Liver Tumor group (JPLT), have made significant contributions to understanding the clinical and histopathological features, as well as the underlying biology of pediatric liver tumors, in particular HB. A new classification of pediatric liver tumors drafted at the international consensus meeting held in Los Angeles, has been incorporated in the recent WHO classification and is currently used by the PHITT (Paediatric Hepatic Malignancy International Tumour Trial) and other therapeutic protocols. This manuscript provides an overview of salient diagnostic features and updates in classification and molecular characterization for the most common pediatric primary liver neoplasms. It also includes a brief overview of other less common but relevant tumors, which should be considered in the differential diagnosis.

Paediatric hepatic angiosarcoma with consumptive hypothyroidism-an important diagnostic pitfall to avoid during evaluation of hepatic vascular tumours

Hepatic angiosarcoma is an extremely rare primary malignant vascular tumour in children with very poor prognosis. Radiological diagnosis of hepatic angiosarcoma is challenging due to overlapping imaging features with other benign vascular hepatic tumours, particularly infantile hepatic haemangioma. Consumptive hypothyroidism is a condition that is almost exclusively associated with infantile hepatic haemangioma and has never been reported in angiosarcoma. We present a case of hepatic angiosarcoma in a 20-month-old girl, associated with consumptive hypothyroidism and, as a result, initially misdiagnosed as infantile hepatic haemangioma. Radiologists should be aware that consumptive hypothyroidism is not a reliable feature to use in excluding paediatric hepatic angiosarcoma. Biopsy should be performed in patients older than 1 year of age or with atypical imaging features.

Pediatric hepatic hemangiomas: spectrum and prognostic significance of initial ultrasound findings

BACKGROUND

Hepatic hemangiomas may be associated with serious complications; however, it is unknown whether ultrasound (US) features can predict complications.

OBJECTIVE

To analyze initial US features of hepatic hemangiomas predictive of complications.

MATERIALS AND METHODS

This is a single-center retrospective cohort study of clinical, biological, and imaging data of infants with hepatic hemangioma between 2000 and 2018. Patients were categorized as having or not having any complication(s). Associations between initial US features and complications were analyzed through logistic regression. Receiver operating characteristic (ROC) curve analyses were performed to determine optimal cutoff values for continuous variables. Stepwise forward logistic regression was used to construct risk prediction models with training and validation sets. Model calibration and discrimination were evaluated using Hosmer-Lemeshow tests, area under the ROC curve, and overall accuracy.

RESULTS

Of 112 infants with hepatic hemangioma, 67 (60%) had focal, 32 (28%) had multifocal, and 13 (12%) had diffuse lesions, with complication rates of 51%, 34%, and 92%, respectively, mostly cardiac (54/57, 95%). The US characteristics of the hemangiomas were diverse. Risk factors for complications included diffuse subtype; large tumor volume (focal forms); elevated peak systolic hepatic arterial velocity (PSV); and hepatic vein dilation. For focal forms, initial tumor volume  >40 ml and PSV >100 cm/s had >70% sensitivity and specificity, respectively, to predict complications; a model including these variables had 75% overall accuracy in the validation set. For multifocal/diffuse forms, a PSV >115 cm/s had sensitivity and specificity to predict complications of  >70%; a model including this variable had 78% overall accuracy in the validation set.

CONCLUSION

Diffuse subtype, large tumor volume, elevated hepatic arterial PSV, and hepatic vein dilation are risk factors for complications of hepatic hemangiomas.

The role of liver transplantation in the care of primary hepatic vascular tumours in children

Liver transplantation (LT) is the standard of care for many liver conditions, such as end-stage liver diseases, inherited metabolic disorders, and primary liver malignancies. In the latter group, indications of LT for hepatoblastoma and hepatocellular carcinoma evolved and are currently available for many non-resectable cases. However, selection criteria apply, as the absence of active metastases. Evidence of good long-term outcomes has validated the LT approach for managing these malignancies in the context of specialist and multidisciplinary approach. Nevertheless, LT's role in treating primary vascular tumours of the liver in children, both benign and malignant, remains somewhat controversial. The rarity of the different diseases and the heterogeneity of pathological definitions contribute to the controversy and make evaluating the benefit/risk ratio and outcomes quite difficult. In this narrative review, we give an overview of primary vascular tumours of the liver in children, the possible indications and the outcomes of LT.

Consumptive Hypothyroidism due to Hepatic Hemangiomas: A Case Series and Review of the Literature

Consumptive hypothyroidism (CH) is a rare and potentially overlooked complication of hepatic hemangiomas (HH) overexpressing the enzyme deiodinase, which converts thyroxine (T4) to reverse triiodothyronine (rT3).

Materials and methods

Here, we report a case series of 3 patients and a systematic review of the literature.

Results

Hypothyroidism (mean serum TSH 52.03 mIU/L) was detected at a mean age of 4.6 months (range 3-6) in 3 infants with infantile hepatic hemangiomas, treated with thyroxine (mean dose 12 µg/kg/day). All received treatment with propranolol (1-3 mg/kg/day) from the mean age of 4 months. Hormonal treatment was stopped at a mean age of 20 months (range 12-30). Hypothyroidism reoccurred in a patient concurrently with the increase of liver lesions, requiring liver transplantation (LT) at age 39 months.Literature review retrieved 42 studies (48 patients): HH (n = 43) were isolated in 24 infants and associated with cutaneous hemangiomas in 19. Hemangiomas were only cutaneous in 5.In the first 43 patients, hypothyroidism was detected at a mean age of 1 month; 21 of 43 patients were prescribed propranolol alone (n = 8) or associated with other medicaments (n = 13); 2 of 43 patients underwent LT. Hormonal treatment consisted of T4 in 35 of 43 patients and T3 in 10.CH associated with only cutaneous and extrahepatic visceral hemangiomas (n = 5), detected at a mean age of 7 months (TSH mean levels at diagnosis of 150.3 mIU/L). Three of 5 patients received treatment with propranolol ± other medicaments. All 5 patients were treated with T4.

Conclusions

Periodical thyroid function assessment is necessary in patients with hepatic hemangiomas, particularly when lesions' size and number increase rapidly.

Pediatric Primary Hepatic Tumors: Diagnostic Considerations

The liver is the third most common site of abdominal tumors in children. This review article aims to summarize current evidence surrounding identification and diagnosis of primary hepatic tumors in the pediatric population based upon clinical presentation, epidemiology, and risk factors as well as classical imaging, histopathological, and molecular diagnostic findings. Readers will be able to recognize the features and distinguish between benign and malignant hepatic tumors within different age groups.

Imaging of solid congenital abdominal masses: a review of the literature and practical approach to image interpretation

Fetal abdominal tumors are rare, usually benign, and cause a great deal of anxiety for expectant parents and the physicians counseling them. In this paper the author reviews the most common fetal abdominal tumors in the liver (hemangioma, mesenchymal hamartoma, hepatoblastoma, metastases) and the kidney (congenital mesoblastic nephroma, Wilms tumor, malignant rhabdoid tumor, and clear cell sarcoma), and suprarenal mass lesions (adrenal neuroblastoma, adrenal hemorrhage, and subdiaphragmatic extralobar pulmonary sequestration). The author describes the imaging approach, imaging appearance and differentiating features of tumors, and differences between fetal and childhood appearances of tumors.

Liver Transplantation for Pediatric Liver Cancer

Unresectable hepatocellular carcinoma (HCC) was first removed successfully with total hepatectomy and liver transplantation (LT) in a child over five decades ago. Since then, children with unresectable liver cancer have benefitted greatly from LT and a confluence of several equally important endeavors. Regional and trans-continental collaborations have accelerated the development and standardization of chemotherapy regimens, which provide disease control to enable LT, and also serve as a test of unresectability. In the process, tumor histology, imaging protocols, and tumor staging have also matured to better assess response and LT candidacy. Significant trends include a steady increase in the incidence of and use of LT for hepatoblastoma, and a significant improvement in survival after LT for HCC with each decade. Although LT is curative for most unresectable primary liver sarcomas, such as embryonal sarcoma, the malignant rhabdoid tumor appears relapse-prone despite chemotherapy and LT. Pediatric liver tumors remain rare, and diagnostic uncertainty in some settings can potentially delay treatment or lead to the selection of less effective chemotherapy. We review the current knowledge relevant to diagnosis, LT candidacy, and post-transplant outcomes for these tumors, emphasizing recent observations made from large registries or larger series.

Diffuse Infantile Hepatic Hemangioendothelioma With Early Central Enhancement in an Adult: A Case Report of CT and MRI Findings

Infantile hepatic hemangioendothelioma (IHH) is the most common vascular tumor of the liver in infancy. Adult with IHH is extremely rare. We presented a diffuse IHH in an adult patient with computed tomography (CT) and magnetic resonance image (MRI) findings.A 39-year-old man was admitted to our hospital because of a 2-year history of abnormal liver function tests and a 7-day history of jaundice. Physical examination revealed enlarged liver. Unenhanced abdominal CT showed enlargement of the liver with diffuse hypodensity. Enhanced CT on the arterial phase revealed multiple centrally enhanced lesions diffusely involved the enlarged liver. The enhanced areas of the lesions became larger on the portal phase and all the lesions became homogeneous enhanced on the delayed phase. These lesions showed heterogeneously hyperintense on T2-weighted image, hypointense on T1-weighted image, and early centrally enhanced on dynamic gadolinium-enhanced MRI, with complete tumor enhancement after 180 s. The patient underwent orthotopic liver transplantation. IHH type 2 was confirmed by pathology. The patient died of tumor recurrence in the liver 4 months after transplantation.Unlike the previously described imaging appearances of IHH, this case showed diffuse nodules with early central enhancement on CT and MRI. Considering the importance of the ability to differentiate IHH from other hepatic tumors, radiologists should be aware of these imaging appearances to establish knowledge of the entire spectrum of IHH.

Imaging findings of multiple infantile hepatic hemangioma associated with cardiac insufficiency

BACKGROUND

Infantile hepatic hemangioma (IHH) as a benign liver tumor in infancy and childhood is commonly associated with high output cardiac failure. The present study aims to describe the imaging findings in a patient who was diagnosed as having multiple IHH with congestive cardiac insufficiency.

METHODS

The imaging findings and clinical manifestations of the patient with multiple IHH associated with cardiac insufficiency were retrospectively reviewed.

RESULTS

Ultrasonography showed multiple intrahepatic lesions with mixed echoes and markedly expanded hepatic veins and the inferior vena cava of the patient. Echocardiography revealed right heart insufficiency and pulmonary hypertension. Contrast-enhanced MRI showed early mild enhancement of lesions and more obvious delayed enhancement. The patient died after combined therapy of surgery and hormone.

CONCLUSIONS

The imaging findings of multiple IHH associated with cardiac insufficiency are typical and diagnostic. Early imaging assessment may facilitate the diagnosis and treatment of the disease.

Hepatic neoplasms in children: a focus on differential diagnosis

Paediatric hepatic neoplasias are rare, accounting for 1-4% of all solid childhood tumors. Liver tumors in children can be classified into benign or malignant; some of the benign lesions can have the potential of malignant transformation. Two-thirds of liver tumors in children are malignant. Hepatoblastoma accounts for two-thirds of malignant liver tumors in children. Other liver malignancies in children include sarcomas, germ cell and rhabdoid tumours, and hepatocellular carcinoma. Benign tumors of the liver in children include vascular tumours, hamartomas, adenomas, and focal nodular hyperplasia. The histology and anatomy of a paediatric liver tumour guides the treatment and prognosis. Although benign and malignant liver masses share some clinical manifestations, treatment and prognosis differ.

Towards an international pediatric liver tumor consensus classification: proceedings of the Los Angeles COG liver tumors symposium

Liver tumors are rare in children, and their diagnoses may be challenging particularly because of the lack of a current consensus classification system. Systematic central histopathological review of these tumors performed as part of the pediatric collaborative therapeutic protocols has allowed the identification of histologic subtypes with distinct clinical associations. As a result, histopathology has been incorporated within the Children's Oncology Group (COG) protocols, and only in the United States, as a risk-stratification parameter and for patient management. Therefore, the COG Liver Tumor Committee sponsored an International Pathology Symposium in March 2011 to discuss the histopathology and classification of pediatric liver tumors, and hepatoblastoma in particular, and work towards an International Pediatric Liver Tumors Consensus Classification that would be required for international collaborative projects. Twenty-two pathologists and experts in pediatric liver tumors, including those serving as central reviewers for the COG, European Société Internationale d'Oncologie Pédiatrique, Gesellschaft für Pädiatrische Onkologie und Hämatologie, and Japanese Study Group for Pediatric Liver Tumors protocols, as well as pediatric oncologists and surgeons specialized in this field, reviewed more than 50 pediatric liver tumor cases and discussed classic and newly reported entities, as well as criteria for their classification. This symposium represented the first collaborative step to develop a classification that may lead to a common treatment-stratification system incorporating tumor histopathology. A standardized, clinically meaningful classification will also be necessary to allow the integration of new biological parameters and to move towards clinical algorithms based on patient characteristics and tumor genetics, which should improve future patient management and outcome.