Clinical outcomes of fetuses with cardiac rhabdomyoma: A case series from a tertiary center

AIMS

The study aims to evaluate the genetic and clinical outcomes of fetal cardiac rhabdomyoma in our tertiary center.

METHODS

Data of cases with cardiac rhabdomyoma detected by fetal echocardiography during antenatal follow-up were analyzed retrospectively.

RESULTS

Nine cases were included in the study. The incidence of cardiac rhabdomyoma was 0.003%. The median fetal diagnosis time was 26th weeks, the most common location was the LV. There was no hemodynamic disorder requiring cardiovascular intervention in any of the cases. Of the eight genetically tested cases, four were tuberous sclerosis complex (TSC) gene-negative, one hereditary TSC2, one de novo TSC1, and two de novo TSC2 gene mutants. Postnatal first-year survival rate of the cases was 88.8%.

CONCLUSIONS

Cardiac rhabdomyoma is a rare fetal and pediatric pathology that generally is a remarkable finding in the clinical process of TSC. Therefore, cases should be evaluated multisystemically and genetic counseling should be given to the family.

Effect of different dose regimens of everolimus in a series of neonates with giant cardiac rhabdomyomas

Everolimus is a mTOR inhibitor that has been increasingly used in high-risk cardiac rhabdomyomas in recent years. There are questions regarding the optimal dose and duration of therapy with everolimus for cardiac rhabdomyomas. The purpose of this study was to examine retrospectively the dosage-efficacy relationship in seven babies diagnosed with rhabdomyoma treated with different everolimus dose regimens retrospectively. Cardiac rhabdomyoma diagnosis was made in six of seven babies during the prenatal period. Indication of everolimus was an obstruction in six patients and supraventricular tachycardia which is resistant to antiarrhythmic drugs in the remaining one patient. The median age was 8 days (range; 2-105 days) at the time of starting everolimus. It was administered at a dose of 0.25 mg twice a day for two days a week in four patients; 0.1 mg/day in two and 0.4 mg/day in one patient. Serum everolimus level was kept between 5 and 15 ng/ml. All seven cases showed significant regression of cardiac rhabdomyoma within four weeks, and supraventricular tachycardia was controlled in two weeks after everolimus administration.This study demonstrates that everolimus was effective in accelerating regression of the cardiac rhabdomyoma. Dose with 2 × 0,25 mg/day, 2 days a week, seems appropriate. However, lower doses such as 0.1 mg/day are also effective. But dose adjustment should be made according to serum level monitoring.

Detection of TSC1/TSC2 mosaic variants in patients with cardiac rhabdomyoma and tuberous sclerosis complex by hybrid-capture next-generation sequencing

Background

Fetal cardiac rhabdomyoma (CR) is strongly associated with tuberous sclerosis complex (TSC), which is caused by variants in TSC1 and TSC2. However, in 10%–15% of patients with clinically confirmed TSC, no TSC1/TSC2 variants are identified by panel sequencing or multiplex ligation‐dependent probe amplification (MLPA).

Methods

We analyzed eight fetuses with CR and their families. No TSC1/TSC2 variants had previously been identified for six of these fetuses, and we suspected the other two families of gonadal mosaicism. We performed next‐generation sequencing (NGS) using CR tissue, umbilical cord tissue, and parental blood. All positive results, involving two paternal semen, were verified by droplet digital polymerase chain reaction (ddPCR).

Results

Four fetuses carried low‐level mosaic variants (0.05%–14.89%), and two only exhibited somatic mosaic variants in the CR tissue (15.76% and 37.69%). Two fathers had gonadal mosaicism (9.07% and 4.86%). We identified nine pathogenic variants in eight fetuses, including one fetus with a second‐hit variant.

Conclusion

The fetuses assessed in this study carried low‐level and somatic mosaic variants, and CR tissue from one fetus exhibited a second‐hit variant. Heterozygous gonadal variants can exist in patients with low‐level mosaicism. Combining NGS with ddPCR improves the accuracy of prenatal TSC diagnosis.

Treatment of Cardiac Rhabdomyomas with mTOR Inhibitors in Children with Tuberous Sclerosis Complex-A Systematic Review

BACKGROUND

Cardiac rhabdomyomas (CRs) are the earliest sign of tuberous sclerosis complex (TSC). Most of them spontaneously regress after birth. However, multiple and/or large tumors may result in heart failure or cardiac arrhythmia. Recently, the attempts to treat CRs with mTOR inhibitors (mTORi) have been undertaken. We reviewed the current data regarding the effectiveness and safety of mTORi in the treatment of CRs in children with TSC.

METHODS

The review was conducted according to the PRISMA guidelines. Medline, Embase, Cochrane library, and ClinicalTrial.gov databases were searched for original, full-text articles reporting the use of mTORi (everolimus or sirolimus) in the treatment of CRs in children with TSC.

RESULTS

Thirty articles describing 41 patients were identified (mostly case reports, no randomized or large cohort studies). Thirty-three children (80.5%) had symptomatic CRs and mTORi therapy resulted in clinical improvement in 30 of them (90.9%). CRs size reduction was reported in 95.1%. Some CRs regrew after mTORi withdrawal but usually without clinical symptoms recurrence. The observed side effects were mostly mild.

CONCLUSIONS

mTORi may be considered as a temporary and safe treatment for symptomatic CRs in children with TSC, especially in high-risk or inoperable tumors. However, high-quality, randomized trials are still lacking.

Efficacy of Everolimus Low-Dose Treatment for Cardiac Rhabdomyomas in Neonatal Tuberous Sclerosis: Case Report and Literature Review

Background: Cardiac rhabdomyomas (CRs) are the most common cardiac tumors in newborns. Approximately 80-90% of cases are associated with tuberous sclerosis complex (TSC). In selective cases, Everolimus has resulted in a remarkable tumoral regression effect in children with TS. The optimal dosage for neonates is still unknown. Case presentation: We describe the use of Everolimus in a neonate with multiple biventricular CRs, causing subaortic obstruction, in which a low-dose treatment (0.1 mg/die), in an effort to maintain serum trough levels of 3-7 ng/mL, was successfully used off-label, without adverse effects. Conclusions: We showed that a low-dose Everolimus regimen may be an effective and safe treatment for CR regression in TS neonates, when the minimum therapeutic range was maintained.

Combination percutaneous and medical management of cardiac rhabdomyomas obstructing tricuspid valve inflow: Case report

BACKGROUND

Cardiac rhabdomyomas can be prenatally diagnosed in patients with tuberous sclerosis complex. Many neonates require no intervention in early life other than close monitoring for regression of tumor over the period of months to years. In rare instances, cardiac rhabdomyomas can result in obstruction to blood flow or decreased ventricular function.

CASE REPORT

We describe the case of a neonate who was prenatally diagnosed with multiple large cardiac rhabdomyomas, one of which caused clinically significant obstruction to prograde blood flow across the tricuspid valve in the newborn period. To address the disturbance to prograde pulmonary blood flow, the patient underwent successful ductal stent placement in the neonatal period. A troponin elevation was noted shortly after birth, but no evidence of coronary compression or involvement was demonstrated by coronary angiography. The patient has subsequently been treated with sirolimus over a period of three months, with noted regression in tumors and improvement in tricuspid valve inflow.

CONCLUSIONS

A brief review of the literature regarding the diagnosis, treatment, and management of neonatal patients with cardiac rhabdomyomas is presented. A combined percutaneous and medical management approach may be of benefit in future cases of rhabdomyomas causing obstruction to pulmonary blood flow.

A Multidisciplinary Approach in Prenatal Diagnosis of TSC With Cardiac Rhabdomyoma as the Initial Symptom

The long-term prognosis of a fetus with cardiac rhabdomyoma (CR) depends on the correlation with tuberous sclerosis complex (TSC). In recent years, the numerous variations of uncertain significance (VUS) of TSC genes produced by high-throughput sequencing have made counseling challenging, studies until now have tended to side-step the tricky topics. Here, we integrated detailed parental phenotype, echocardiography, neuro MRI, and genetic information to conduct a comprehensive evaluation of 61 CR fetuses. As a result, multiple CRs and cerebral lesions appeared in 90 and 80%, respectively of fetuses with pathogenic (P)/likely pathogenic (LP) TSC1/TSC2 variations. Overall, 85.7% of the live-born infants with P/LP presented with TSC-associated signs. While, 85.7% of VUS without nervous findings had good prognoses. Genetic evidence and cerebral MRI findings are the most sensitive index to assess long-term prognosis, which complement and confirm each other for a TSC diagnosis. In total, 68.9% of fetuses with CR could benefit from this multidisciplinary approach, which turned out to be potentially clinically actionable with precise clinical/genetic diagnosis or had a foreseeable outcome. Our practice provides a practical and feasible solution for perinatal management and prognostic guidance for fetuses with CR.

Everolimus for cardiac rhabdomyomas in children with tuberous sclerosis. The ORACLE study protocol (everOlimus for caRdiac rhAbdomyomas in tuberous sCLErosis): a randomised, multicentre, placebo-controlled, double-blind phase II trial

INTRODUCTION

Tuberous sclerosis complex is a rare genetic disorder leading to the growth of hamartomas in multiple organs, including cardiac rhabdomyomas. Children with symptomatic cardiac rhabdomyoma require frequent admissions to intensive care units, have major complications, namely, arrhythmias, cardiac outflow tract obstruction and heart failure, affecting the quality of life and taking on high healthcare cost. Currently, there is no standard pharmacological treatment for this condition, and the management includes a conservative approach and supportive care. Everolimus has shown positive effects on subependymal giant cell astrocytomas, renal angiomyolipoma and refractory seizures associated with tuberous sclerosis complex. However, evidence supporting efficacy in symptomatic cardiac rhabdomyoma is limited to case reports. The ORACLE trial is the first randomised clinical trial assessing the efficacy of everolimus as a specific therapy for symptomatic cardiac rhabdomyoma.

METHODS

ORACLE is a phase II, prospective, randomised, placebo-controlled, double-blind, multicentre protocol trial. A total of 40 children with symptomatic cardiac rhabdomyoma secondary to tuberous sclerosis complex will be randomised to receive oral everolimus or placebo for 3 months. The primary outcome is 50% or more reduction in the tumour size related to baseline. As secondary outcomes we include the presence of arrhythmias, pericardial effusion, intracardiac obstruction, adverse events, progression of tumour reduction and effect on heart failure.

CONCLUSIONS

ORACLE protocol addresses a relevant unmet need in children with tuberous sclerosis complex and cardiac rhabdomyoma. The results of the trial will potentially support the first evidence-based therapy for this condition.

Clinical outcome of prenatally suspected cardiac rhabdomyomas of the fetus

Background The main objective of this retrospective analysis in a large tertiary center was the clinical outcome of prenatally diagnosed cardiac rhabdomyomas as well as the identification of factors influencing fetal prognosis. Methods A total of 45 cases of fetuses with prenatally suspected rhabdomyoma and their clinical outcome were analyzed retrospectively. A review of the literature was also performed. Results In five cases, after a tuberous sclerosis complex (TSC) mutation had been confirmed, termination of pregnancy was chosen. In 30 cases postnatal data were available. In 93% TSC was confirmed clinically or by mutational analysis. Two thirds of fetuses presented with multiple tumor while one third presented with a solitary tumor. In two fetuses mild pericardial effusions were observed. Another three fetuses presented with extrasystoles prenatally. No hydrops fetalis or fetal perinatal demise were observed. After birth 41% of the children suffered from arrhythmia including supra- and ventricular tachycardia, Wolff-Parkinson-White syndrome and atrioventricular block. One child received a Fontan procedure with Glenn anastomosis. Another child with a dilatative cardiomyopathy and a left ventricular ejection fraction of 15% died. Fifty-two percent of the children with TSC suffered from epilepsy ranging from absence epilepsy and West syndrome to generalized seizures with a frequency of up to 40 per day. Two children underwent neurosurgery to remove the epileptogenic focus. One child suffered from TSC and Lesch-Nyhan disease. In another case Beckwith-Wiedemann syndrome was identified as the causative disorder. Conclusion Rhabdomyoma are rare, benign tumors. There is an association with TSC. In the majority of cases rhabdomyoma are not hemodynamically relevant and do not increase in size. The quality of life of affected patients is impaired particularly due to epilepsy and psychomotor retardation.

Antenatal screening and diagnosis of tuberous sclerosis complex by fetal echocardiography and targeted genomic sequencing

Although fetal cardiac rhabdomyoma can be the initial finding in patients with tuberous sclerosis complex (TSC), the challenges of precise genetic diagnosis of TSC can now be potentially overcome by new whole or targeted genomic sequencing. The goals of this study were to investigate the correlation between suspected cardiac rhabdomyoma and TSC to provide the information for a prenatal diagnosis of TSC and to validate the TSC genotype in this cohort of fetuses with suspected prenatal cardiac rhabdomyoma.We retrospectively analyzed 10,728 fetal echocardiograms from January 2013 to March 2016 in our institution. A total of 32 fetuses were suspected of having cardiac rhabdomyomas. Among them, 15 subjects met the inclusion criteria and provided written consent. Samples from fetuses (n = 13 after terminations) and newborns (n = 2) were available for targeted genomic sequencing of the exons and introns of the TSC1 and TSC2 genes and the adjacent 10 base pairs and for validated studies using Sanger sequencing.Among the 15 subjects with suspected cardiac rhabdomyoma and TSC genomic sequencing data, 7 subjects were familial and 8 subjects were sporadic cases. Fetal echocardiography showed a single tumor in 2 fetuses and multiple tumors in 13 fetuses. Gene sequencing analysis showed no mutation of the TSC1 or TSC2 gene in 2 subjects with a single tumor but positive mutations in all 13 subjects with multiple tumors. Among the latter, 5 mutations were "pathogenic" and have been previously reported (4 familial and 1 sporadic). Six new mutations were "likely pathogenic" and had not been previously reported (3 familial and 3 sporadic); 1 was of "uncertain significance" (sporadic), and 1 was suspected of being "likely benign" (sporadic).Prenatal suspected cardiac rhabdomyoma detected by fetal echocardiography should raise the suspicion of TSC. In fetuses with multiple tumors, especially the familial cases, genomic sequencing has a high yield of detecting TSC-causing genes. Patient history, prenatal fetal echocardiography, and targeted genomic sequencing may facilitate screening for, diagnosis of, and counseling for TSC.

Prenatally Diagnosis and Outcome of Fetuses with Cardiac Rhabdomyoma - Single Centre Experience

BACKGROUND

Cardiac rhabdomyoma (CRs) are the most common primary tumour of the heart in infants and children. Usually are multiple and, basing on the location can cause a haemodynamic disturbance, dysrhythmias or heart failure during the fetal and early postnatal period. CRs have a natural history of spontaneous regression and are closely associated with tuberous sclerosis complex (TSC). It has an association with tuberous sclerosis (TS), and in those, the tumour may regress and disappear completely, or remain consistent in size.

AIM

We aimed to evaluate the prenatal diagnosis, clinical presentation and outcome of CRs and their association with TSC in a single centre. The median follow-up period was three years (range: 6 months - 5 years).

MATERIAL AND METHODS

We reviewed medical records of all fetuses diagnosed prenatally with cardiac rhabdomyoma covering the period January 2010 to December 2016 which had undergone detailed ultrasound evaluation at a single centre with limited technical resources.

RESULTS

Twelve fetuses were included in the study; mostly had multiple tumours and a total of 53 tumours were identified in all patients - the maximum was one fetus with16 tumours. All patients were diagnosed prenatally by fetal echocardiography. In two patient's haemodynamic disturbances during the fetal period was noted and pregnancies have been terminated. After long consultation termination of pregnancy was chosen by the parents in totally 8 cases. In four continuing pregnancies during the first year of live tumours regressed. TSC was diagnosed in all patients during the follow-up.

CONCLUSIONS

Cardiac rhabdomyoma are benign from the cardiovascular standpoint in most affected fetuses. An early prenatal diagnosis may help for an adequate planning of perinatal monitoring and treatment with the involvement of a multidisciplinary team. Large tumour size, the number of tumours and localisation may cause hydrops, and they are significantly associated with poor neonatal outcome.

Regression of massive cardiac rhabdomyoma on everolimus therapy

Cardiac rhabdomyoma is the primary feature of the genetic disease, tuberous sclerosis complex, the most common cardiac tumor diagnosed in neonates and infants. Spontaneous regression is observed in most cases, but these tumors may cause hemodynamic instability, arrhythmias or other complications. We describe the case of a critically ill neonate, resuscitated after cardiac arrest secondary to massive locally invasive cardiac rhabdomyoma, who was successfully treated with everolimus (mammalian target of rapamycin [mTOR] inhibitor). Rapid tumor regression was observed on echocardiography, but it was unlikely that it was confounded by the natural disease course of regression. The presented case suggests that mTOR inhibitors may play a significant role in the treatment of large cardiac rhabdomyomas in critically ill neonates.

Use of mTOR inhibitor everolimus in three neonates for treatment of tumors associated with tuberous sclerosis complex

BACKGROUND

Tuberous sclerosis complex is characterized by the growth of benign tumors in multiple organs, caused by the disinhibition of the mammalian target of rapamycin (mTOR) protein. mTOR inhibitors, such as everolimus, are used in patients with tuberous sclerosis complex, mainly to reduce the size of renal angiomyolipomas and subependymal giant cell astrocytomas. There are minimal data available regarding its use during the neonatal period.

METHODS

We report clinical and pharmacological data of three neonates treated with the mTOR inhibitor everolimus (two hemodynamically significant cardiac rhabdomyomas and one voluminous subependymal giant cell astrocytoma).

RESULTS

Beneficial clinical responses were observed in all three patients and the medication was generally well-tolerated. Optimal dose was 0.1 mg orally once daily and was confirmed with therapeutic drug monitoring.

CONCLUSION

Everolimus is a promising pharmacological approach to treat clinically significant inoperable cardiac rhabdomyomas or subependymal giant cell astrocytoma associated with tuberous sclerosis complex during the neonatal period.

Fetal intracardiac rhabdomyoma in beckwith-wiedemann syndrome

Fetal cardiac tumors are a rare finding in prenatal ultrasonography. Most of them are rhabdomyoma, which are thought to be pathognomonic for tuberous sclerosis complex. We present an infant with prenatally diagnosed cardiac rhabdomyoma (CR), who was found to suffer from Beckwith-Wiedemann syndrome (BWS). This congenital overgrowth syndrome is characterized by macrosomia, macroglossia, omphalocele, hypoglycemia, and hemihypertrophy. BWS patients have an increased risk for formation of benign and malignant tumors, typically intra-abdominally located, but, to the best of our knowledge, fetal CRs have not been reported before. BWS must be added to the list of differential diagnoses and to the prenatal counseling of the parents in cases of prenatal detection of CR.

A cardiac rhabdomyoma in a Guinea pig

A guinea pig (9-week-old) that had been placed in a control group for a pharmacological test was found to have a single nodule on the surface of the right ventricular wall. In a transverse section of the heart after fixation, a whitish mass was found that extended from the subendocardium to the subepicardium of the right ventricular wall. Histopathological examination revealed a spongy network consisting of vacuolated spaces in the myocardium of the right ventricle extending to the myocardium and subepicardium of the right atrium. The vacuolated space was PAS-positive. Immunohistochemical examinations revealed that the lesions contained striated fibers that were positive for anti-desmin and anti-myoglobin. Electron micrographs revealed the lesions resulting in affected striated muscle fibers and accumulations of many glycogen granules. Based on the findings, the lesions were diagnosed as a cardiac rhabdomyoma. This is the first report of application of immunohistochemical examinations to diagnosis of cardiac rhabdomyoma in the guinea pig.

Giant rhabdomyoma of the right ventricle

A giant intrathoracic mass causing foetal dysrhythmias, polyhydramnios and foetal hydrops necessitated a caesarean section in a male infant of 35 weeks gestation. Despite the benign histology of cardiac rhabdomyomas and the observation of spontaneous regression, there may be significant associated morbidity and mortality, especially in neonates. There is a high incidence of associated tuberous sclerosis.