Fetal and neonatal cardiac tumors

Pediatric primary cardiac tumors: Diagnosis and treatment

Primary cardiac tumors are rare in pediatrics. Their clinical presentation differs among the various age groups (fetus to the young adult). Our discussion focuses on the diagnosis and treatment of rhabdomyomas, fibromas, myxomas, and pericardial teratomas in the fetus and neonatal stages. Fetal diagnosis has been described in association with rhabdomyomas, fibromas, and pericardial teratomas. It is made by echocardiography prompted by fetal dysrhythmias, nonimmune hydrops, intrauterine growth restriction, and familial tuberous sclerosis. Based on our experience, it is of the utmost importance to refer these patients to a tertiary center for detailed evaluation, follow-up, and delivery. Tumor diagnosis in the neonatal age group may be prompted by a murmur, dysrhythmia, conduction block, and hemodynamic compromise or hypoxemia due to right or left inflow or outflow tract obstruction. Prenatal diagnosis of a hemodynamically significant mass mandates the presence of a neonatal intensivist in the delivery room for prompt initiation of advanced life support (intubation, mechanical ventilation, and central venous access), and early initiation of prostaglandin E(1) to establish ductus arteriosus patency. Severe inflow obstruction associated with a restrictive atrial septum may require balloon atrial septostomy. Emergent transvenous pacing is indicated in the face of high-degree atrioventricular block. Early surgical removal of the mass after initial stabilization in the neonatal or cardiac intensive care unit may be indicated.

Outcome of antenatally diagnosed cardiac rhabdomyoma: case series and a meta-analysis

OBJECTIVES

Rhabdomyoma, the most common primary fetal cardiac tumor, is often associated with tuberous sclerosis (TS). We aimed to evaluate outcome in cases diagnosed with fetal cardiac rhabdomyoma.

METHODS

This study presents 11 cases with fetal cardiac rhabdomyoma. In addition, all relevant published cases of antenatally diagnosed cardiac rhabdomyoma since 1982 were identified from MEDLINE. We evaluated the following risk factors associated with clinical impact and perinatal outcome: family history of TS, gestational age at diagnosis, tumor size, site and number of tumors, tumor progression, and associated intracardiac and extracardiac anomalies.

RESULTS

In this meta-analysis, 138 cases, including nine newly added by us, were categorized into Group A (107 live babies) and Group B (16 neonatal deaths and 15 intrauterine fetal deaths). Univariate analysis showed that large cardiac tumors (P < 0.0001), fetal dysrhythmia (P < 0.0001) and hydrops (P < 0.0001) were strong predictors of neonatal outcome. Tumor size >or= 20 mm (relative risk (RR), 20.6; 95% CI, 2.2-195.9; P = 0.009) and fetal dysrhythmia (RR, 13.6; 95% CI, 2.9-62.3; P = 0.001) were significantly associated with neonatal morbidity. TS, present in 85/133 (63.9%) cases, was significantly associated with multiple cardiac tumors (P < 0.0001) and family history of TS (P = 0.02).

CONCLUSIONS

Large tumor size and hydrops are significantly associated with poor neonatal outcome, whereas family history of TS and multiple fetal cardiac tumors are associated with TS. Any sonographic detection of a fetal cardiac tumor should warrant further investigation for the possible presence of associated disorders.

Spectrum and outcome of prenatally diagnosed fetal tumors

OBJECTIVE

To describe the spectrum of prenatally diagnosed fetal tumors, and the course and fetal outcome in affected pregnancies.

METHODS

This was a retrospective study in two German tertiary referral centers of 84 fetuses with tumors diagnosed in the prenatal period. The tumors were classified according to their location and histology.

RESULTS

The most common site of origin was the heart (20/84, 23.8%), followed by the face and neck region (19/84, 22.6%) and the abdomen (16/84, 19%). Lymphangiomas (21/84, 25%) and rhabdomyomas (19/84, 22.6%) comprised half of the tumor histology. Less frequently, teratomas (14/84, 16.6%) and hemangiomas (12/84, 14.2%) were seen. Complications included arrhythmia in cases with rhabdomyoma (8/19, 42%) and signs of heart failure in cases with hemangioma (4/12, 33%) and teratoma (4/14, 28.6%). The overall survival rate was 75%. Cases with either a histological diagnosis of teratoma or tumor located in the brain had the worst prognosis.

CONCLUSION

The combination of sonographic features and their location allows reliable prediction of the histological type in the vast majority of fetal tumors. Malignancy, associated malformations and aneuploidy are observed infrequently. Knowledge of the presence of a fetal tumor facilitates close surveillance by a specialized team, which might lead to early recognition of problems and improve perinatal outcome.

Functional characterisation of the TSC1-TSC2 complex to assess multiple TSC2 variants identified in single families affected by tuberous sclerosis complex

Background

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterised by seizures, mental retardation and the development of hamartomas in a variety of organs and tissues. The disease is caused by mutations in either the TSC1 gene on chromosome 9q34, or the TSC2 gene on chromosome 16p13.3. The TSC1 and TSC2 gene products, TSC1 and TSC2, interact to form a protein complex that inhibits signal transduction to the downstream effectors of the mammalian target of rapamycin (mTOR).

Methods

We have used a combination of different assays to characterise the effects of a number of pathogenic TSC2 amino acid substitutions on TSC1–TSC2 complex formation and mTOR signalling.

Results

We used these assays to compare the effects of 9 different TSC2 variants (S132C, F143L, A196T, C244R, Y598H, I820del, T993M, L1511H and R1772C) identified in individuals with symptoms of TSC from 4 different families. In each case we were able to identify the pathogenic mutation.

Conclusion

Functional characterisation of TSC2 variants can help identify pathogenic changes in individuals with TSC, and assist in the diagnosis and genetic counselling of the index cases and/or other family members.

A review of findings in fetal cardiac section drawings, part 1: The 4-chamber view

OBJECTIVES

The goal of this presentation is to review some of the common and rare fetal heart abnormalities and to provide an easy approach to these findings with schematic drawings.

METHODS

Over the past 10 years, we collected cases in which the common views of the heart were abnormal and the differential diagnoses that existed for each. The presentation shows the normal sonographic sections and then variations of these sections and the associated anomalies. We used illustrative drawings to present these findings, enabling us to point out the main sonographic features of abnormalities of the heart.

RESULTS

The work reviews 17 fetal heart abnormalities in schematic drawings.

CONCLUSIONS

This short review highlights several of the anomalies that can be recognized on the common sonographic views. The drawings tend to simplify the findings but serve as a basis for those doing fetal echocardiography when they encounter an unusual finding.

Left ventricular rhabdomyoma with severe left ventricular outflow tract obstruction: development of delayed hemiplegia after cardiopulmonary bypass

The incidence of cardiac tumors increased with the improvement of imaging techniques in infants. Rhabdomyomas are the most common tumors in this group of patients. We herein report a 40-day-old male patient with left ventricular rhabdomyoma. The tumor caused syncope attack and supraventricular tachycardia. An emergency operation was planned and the life-threatening lesion was excised via left ventriculotomy. The patient was extubated on postoperative sixth hour and discharged from hospital on the sixth day of the postoperative period without any problem. This successful operation encourages us not to hesitate to perform an operation in newborns with cardiac neoplasms causing hemodynamic instability.

A Patient with Cardiac Fibroma and a Subvalvular Aortic Stenosis Caused by a Subvalvular Membrane

In this report, we describe a patient with two uncommon cardiac abnormalities: a subvalvular membrane in the left ventricular outflow tract and a cardiac fibroma (CF) in the left atrium. This 56-year-old patient presented with a known subaortic stenosis caused by a subvalvular membrane, a large mass attached to the interatrial septum in the immediate proximity of mitral valve, and a cardiac history of infective endocarditis. Initially, the mass was thought to be an old vegetation. However, the histology of this lesion diagnosed a CF. Primary cardiac tumors are rare. Myxoma and papillary fibroelastoma are the most frequently encountered primary cardiac tumors. CF is usually diagnosed during childhood. In this case, the presentation of the CF was atypical for 3 reasons: the tumor was diagnosed in an adult, the fibroma was pedunculated, and not located within the myocardium but originated from the interatrial septum.

Real-time 3-dimensional echocardiographic features of fetal cardiac tumor

We present a case of fetal cardiac tumors diagnosed using conventional 2-dimensional (2D) fetal echocardiography and real-time 3-dimensional (3D) echocardiography. Conventional 2D echocardiography revealed multiple cardiac tumors involving the right atrium, interventricular septum, and right and left ventricles. Real-time 3D echocardiography with instantaneous volume rendering showed the cardiac tumors in motion. The advantages and disadvantages of real-time 3D fetal echocardiography are discussed.

Primary tumors of the heart: experience at the University Hospital of the West Indies

BACKGROUND

An analysis of primary cardiac tumors in the English-speaking Caribbean has never been previously conducted. This paper is an attempt to fill this void.

METHODS

A retrospective review of autopsy and surgical pathology records of the Department of Pathology at the University Hospital of the West Indies was carried out in search of all primary cardiac tumors.

RESULTS

Altogether, 15 patients with primary cardiac tumors were identified. Twelve patients had myxomas, 2 of which were newborn infants. There were 2 cases of fibroma and 1 of rhabdomyoma, also in children. No malignant tumors were identified. Of the 10 adult patients all of whom had myxoma, there were 5 men and 5 women whose ages ranged from 33 to 83 years with a mean of 52 years. Echocardiography was used in making the diagnosis of cardiac tumor in all but one of these cases. All adult patients were symptomatic, with shortness of breath, often accompanied by congestive cardiac failure, being the most common symptom. One patient presented with embolic phenomena.

CONCLUSION

This analysis of the clinicopathologic features of primary cardiac neoplasms represents the first of its kind in the English-speaking Caribbean. While the total number of cases was small, there appears to be a disproportionate number of pediatric tumors representing a third of the total. Furthermore, the distribution of tumor types within the pediatric population was dissimilar to that usually seen with only one rhabdomyoma.

Cardiac tumours in children

Cardiac tumours are benign or malignant neoplasms arising primarily in the inner lining, muscle layer, or the surrounding pericardium of the heart. They can be primary or metastatic. Primary cardiac tumours are rare in paediatric practice with a prevalence of 0.0017 to 0.28 in autopsy series. In contrast, the incidence of cardiac tumours during foetal life has been reported to be approximately 0.14%. The vast majority of primary cardiac tumours in children are benign, whilst approximately 10% are malignant. Secondary malignant tumours are 10-20 times more prevalent than primary malignant tumours. Rhabdomyoma is the most common cardiac tumour during foetal life and childhood. It accounts for more than 60% of all primary cardiac tumours. The frequency and type of cardiac tumours in adults differ from those in children with 75% being benign and 25% being malignant. Myxomas are the most common primary tumours in adults constituting 40% of benign tumours. Sarcomas make up 75% of malignant cardiac masses. Echocardiography, Computing Tomography (CT) and Magnetic Resonance Imaging (MRI) of the heart are the main non-invasive diagnostic tools. Cardiac catheterisation is seldom necessary. Tumour biopsy with histological assessment remains the gold standard for confirmation of the diagnosis. Surgical resection of primary cardiac tumours should be considered to relieve symptoms and mechanical obstruction to blood flow. The outcome of surgical resection in symptomatic, non-myxomatous benign cardiac tumours is favourable. Patients with primary cardiac malignancies may benefit from palliative surgery but this approach should not be recommended for patients with metastatic cardiac tumours. Surgery, chemotherapy and radiotherapy may prolong survival. The prognosis for malignant primary cardiac tumours is generally extremely poor.

Neoplasias neonatales: experiencia de un centro

INTRODUCTION

Malignant tumors are uncommon in the neonatal period and benign tumors may have malignant potential.

OBJECTIVES

To describe the neoplasms diagnosed and treated in newborns (</= 28 days of life) in the Hospital Universitario de Canarias and their association with congenital abnormalities and to evaluate prenatal diagnosis of these tumors.

PATIENTS AND METHODS

The medical records of patients with neoplasms diagnosed during the neonatal period in the previous 25 years in our hospital were retrospectively reviewed. The variables analyzed were the percentage of neonatal neoplasms among the total number of cancer cases in children aged less than 14 years, their incidence among all the newborns in our hospital, sex, year of diagnosis, age at clinical diagnosis, the presence or absence of prenatal diagnosis, type of tumor (histologic diagnosis), association with syndromes or other congenital anomalies, treatment, and long-term outcome.

RESULTS

Of 260 neoplasms diagnosed in our unit from 1980, 16 (6.1 %) were diagnosed in the neonatal period. The incidence of neonatal neoplasms was estimated to be 276.5 per million live births. Males accounted for 43.8 % and females for 56.2 %, with a mean age at diagnosis of 5.5 days (range 1-28 days). Five neonates (31.2 %) had a prenatal diagnosis, 60 % of which were made in the last 7 years of the study period. A further five newborns were diagnosed at the initial neonatal examination. Histologic diagnoses were neuroblastoma (n = 5; 31.2 %), teratoma/ germ cell tumor (n = 4; 25 %), soft tissue sarcoma (one fibrosarcoma of the thigh and two hemangiopericytoma of the back and heart; 18.8 %), and one case each of mesoblastic nephroma, cerebral tumor (ependymoblastoma), melanoma (associated with giant congenital melanocytic nevi), and acute leukemia (associated with Down syndrome). Treatment consisted of surgery alone (n = 10; 62.5 %) and surgery plus chemotherapy (n = 5; 31.2 %); one patient received no treatment. The overall actuarial survival rate was 87.5 %. Sequelae were observed in 33.3 % of survivors.

CONCLUSIONS

The neoplasms most frequently diagnosed in the neonatal period were solid tumors, mainly neuroblastoma and teratomas/germ cell tumors; 12.5 % were associated with syndromes or congenital anomalies. In the last 7 years, the prenatal diagnosis of these entities has improved. Most of the neoplasms responded to therapy, mainly surgery, and long-term outcome was favorable.

Left Ventricular Fibroma Mimicking an Acute Coronary Syndrome

Cardiac fibromas are exceedingly rare neoplasms. We report the case of a 21-year-old woman who presented with symptoms that were initially misinterpreted as an acute coronary syndrome. Radical surgical resection was undertaken and was considered curative, as the mass histology was consistent with a benign fibroma.

Pluripotent stem cells and their niches

The ability of stem cells to self-renew and to replace mature cells is fundamental to ontogeny and tissue regeneration. Stem cells of the adult organism can be categorized as mono-, bi-, or multipotent, based on the number of mature cell types to which they can give rise. In contrast, pluripotent stem cells of the early embryo have the ability to form every cell type of the adult body. Permanent lines of pluripotent stem cells have been derived from preimplantation embryos (embryonic stem cells), fetal primordial germ cells (embryonic germ cells), and malignant teratocarcinomas (embryonal carcinoma cells). Cultured pluripotent stem cells can easily be manipulated genetically, and they can be matured into adult-type stem cells and terminally differentiated cell types in vitro, thereby, providing powerful model systems for the study of mammalian embryogenesis and disease processes. In addition, human embryonic stem cell lines hold great promise for the development of novel regenerative therapies. To fully utilize the potential of these cells, we must first understand the mechanisms that control pluripotent stem cell fate and function. In recent decades, the microenvironment or niche has emerged as particularly critical for stem cell regulation. In this article, we review how pluripotent stem cell signal transduction mechanisms and transcription factor circuitries integrate information provided by the microenvironment. In addition, we consider the potential existence and location of adult pluripotent stem cell niches, based on the notion that a revealing feature indicating the presence of stem cells in a given tissue is the occurrence of tumors whose characteristics reflect the normal developmental potential of the cognate stem cells.

Fetal Echocardiography Service in Qatar: Establishment, Challenges and Outcome

A prospective observational study at the newly estab-lished Fetal Medicine Unit, Hamad Hospital, Qatar; evalu-ated the impact of the service on the detection rate of criti-cal congenital heart defects, patterns of referral and sub-sequent yield for structural congenital heart disease in a population with a significant proportion of high risk fac-tors.

Of 391 pregnant females examined between January 2003 and December 2004, 58 (14.8%) had fetal cardiac abnormalities of which 23 (5.8% of total referrals) had major structural malformations of the heart. Cases of fetal congenital heart disease had further evaluation us-ing real time three-dimensional echocardiography (RT3DE) which is new equipment in the paediatric cardi-ology department. All cases with cardiac defects whether minor or major had follow up fetal echocardiography. Neonatal echocardiography confirmed the diagnosis in all cases with major defects (100% specificity). False positive cases that were found to be normal post natal were 1% of the total cases referred (12% of cases with congenital mal-formation). False negative cases were 1% and all had a small ventricular septal defect (VSD) except for one Down's syndrome with a very large VSD.

Three patients needed urgent Caesarean section (CS) deliveries, one with complete heart block (HB) and two with supraventricular tachycardia (SVT). One patient traveled abroad as the fetus had left isomerism and major cardiac defects and complete HB. Fifteen newborns had to receive prostaglandin based on the fetal diagnosis before being seen by paediatric cardiologists. There was no termination of pregnancy due to major cardiac defects even in cases of HLHS.

The preliminary results of this clinic are very satisfac-tory and have affected favorably the outcome of the new-borns with congenital heart defects. It is hoped that the results of this study will encourage more referrals to the FMU.

Resection of an obstructive neonatal cardiac myxoma of the infundibulum

Myxoma, the most common primary cardiac tumor in adults, is rare in neonates. We describe a myxoma arising from the infundibulum of the right ventricle causing significant outflow tract obstruction in an otherwise normal newborn. Serial echocardiograms revealed an increasing gradient across the right ventricular outflow tract prompting surgery. The patient underwent successful excision of the myxoma with an uneventful recovery.

The genetic basis for cardiac remodeling

Cardiomyopathies are primary disorders of cardiac muscle associated with abnormalities of cardiac wall thickness, chamber size, contraction, relaxation, conduction, and rhythm. They are a major cause of morbidity and mortality at all ages and, like acquired forms of cardiovascular disease, often result in heart failure. Over the past two decades, molecular genetic studies of humans and analyses of model organisms have made remarkable progress in defining the pathogenesis of cardiomyopathies. Hypertrophic cardiomyopathy can result from mutations in 11 genes that encode sarcomere proteins, and dilated cardiomyopathy is caused by mutations at 25 chromosome loci where genes encoding contractile, cytoskeletal, and calcium regulatory proteins have been identified. Causes of cardiomyopathies associated with clinically important cardiac arrhythmias have also been discovered: Mutations in cardiac metabolic genes cause hypertrophy in association with ventricular pre-excitation and mutations causing arrhythmogenic right ventricular dysplasia were recently discovered in protein constituents of desmosomes. This considerable genetic heterogeneity suggests that there are multiple pathways that lead to changes in heart structure and function. Defects in myocyte force generation, force transmission, and calcium homeostasis have emerged as particularly critical signals driving these pathologies. Delineation of the cell and molecular events triggered by cardiomyopathy gene mutations provide new fundamental knowledge about myocyte biology and organ physiology that accounts for cardiac remodeling and defines mechanistic pathways that lead to heart failure.

Tumors associated with sudden infant and childhood death

Tumors are rare causes of sudden death in infancy and early childhood. The goals of this study were to determine the types and frequency of the tumors associated with sudden death occurring in cases between birth and age 3 years. The San Diego Sudden Infant Death Syndrome/sudden unexplained death in childhood (SUDC) Research Project database and the literature were reviewed retrospectively. Sixty-eight cases, with the most (84%) affecting the heart and brain, were identified. Tumors are a rare but significant cause of sudden death in infancy and early childhood, and their diagnosis may have significant genetic implications for planning future pregnancies. The diagnosis of these lesions can be established only after thorough postmortem examination.

Precise prenatal diagnosis of tuberous sclerosis by sequencing the TSC2 gene

BACKGROUND

The presumptive prenatal diagnosis of tuberous sclerosis (TSC) previously depended upon fetal imaging. Cloning of the two TSC genes (TSC1 and TSC2) now enables precise molecular diagnosis by gene sequencing. We used this approach for the prenatal diagnosis of a fetus showing multiple intracardiac tumors.

METHODS

DNA extracted from cultivated amniotic fluid cells underwent sequencing of all coding regions and exon-intron boundaries of the TSC1 and TSC2 genes.

RESULTS

A mutation (R611Q) was found in exon 16 of the TSC2 gene. Thus far, neither clinically unaffected parents has provided blood samples for mutation analysis.

CONCLUSION

For the first time, mutation analysis of a TSC gene enabled a precise prenatal diagnosis.

Perinatal (fetal and neonatal) germ cell tumors

BACKGROUND/PURPOSE

Germ cell tumors are relatively common in the fetus and neonate and are the leading neoplasms in some perinatal reviews. The purpose of this study is to focus on the fetus and neonate in an attempt to determine the various ways germ cell tumors differ clinically and morphologically from those occurring in the older child and adult and to show that certain types of tumors have a better prognosis than others.

METHODS

The author conducted a retrospective review of perinatal teratomas and other germ cell tumors reported in the literature and of patients treated and followed up at Children's Hospital San Diego and Children's Hospital Los Angeles. Only fetuses and infants less than 2 months of age with adequate clinical and pathologic data were accepted for review.

RESULTS

Five hundred thirty-four fetuses and neonates presented with teratomas diagnosed prenatally (n = 226) and at birth (n = 309). The most common initial finding was a mass, noted either by antenatal sonography or by physical examination during the neonatal period, with signs and symptoms referable to the site of origin. Overall polyhydramnios was next followed by respiratory distress and stillbirth. The number of mature and immature teratomas was approximately the same. The incidence of teratoma with yolk sac tumor either at presentation or at recurrence was 5.8%, and the survival rate was 39%. Sacrococcygeal teratomas had the highest incidence of yolk sac tumor at 10%. Recurrent disease in the form of either teratoma or yolk sac tumor developed in 5% of patients. All individuals with teratomas who survived received surgical resection.

CONCLUSIONS

Some germ cell tumors of the fetus and neonate have a better prognosis than others. Neonates with gastric teratomas have the best survival rates, and those with intracranial germ cell tumors the worst. Fetuses with teratomas detected antenatally have 3 times the mortality rate compared with postnatally diagnosed neonates. Although perinatal teratomas have a relatively low recurrence rate of 5%, close follow-up with imaging studies and serum alpha-fetoprotein determinations is is strongly recommended. Surgical resection alone may be adequate therapy for teratomas with nonmetastatic, microscopic foci of yolk sac tumor. In the nonteratoma group, patients with pure yolk sac tumor and gonadoblastoma have a much better outcome than those with choriocarcinoma, which has a very low survival of rate of 12%. Currently, the use of platinum-based combination chemotherapy has significantly improved the survival rate of infants with advanced malignant germ cell tumor disease.