Prediction of postnatal arrhythmia in fetuses with cardiac rhabdomyoma

A case of massive fetal cardiac rhabdomyoma: ultrasound features and management

We report the case of a massive fetal cardiac rhabdomyoma recently occurred at our clinic. A woman at 23 weeks of gestational age was referred to our center for a fetal cardiac echogenic mass of 26 mm detected at the second-trimester screening ultrasound. During pregnancy, though, the mass progressively increased its dimensions until reaching 48 mm in diameter at 37 weeks of gestation. Fetal echoencephalography and brain magnetic resonance did not show any further fetal anomalies, but molecular genetic testing at amniocentesis revealed a heterozygotic missense variant of gene TSC2 associated with Tuberous Sclerosis. The mass was therefore most likely preferable to a single large rhabdomyoma of gradually increasing dimensions. The baby was delivered at term with a cesarean section. Because of the rhabdomyoma remarkable size and newborn ECG electrical alterations, postnatal therapies with Flecainide and Everolimus were started. Everolimus treatment led to a significant and progressive reduction in the cardiac mass volume. This case, therefore, shows the efficacy of what seems to be a promising treatment in pediatric patients with large rhabdomyomas.Learning points:Rhabdomyomas may present with different features: most often they appear as multiple masses along the interventricular sept, but they may also appear as a single large thoracic mass.When a rhabdomyoma is suspected, genetic counseling is recommended.Both before and after birth, a multidisciplinary approach is useful to choose the appropriate therapy for the newborn.mTOR inhibitors therapies look like promising therapeutic approaches to stimulate the involution of rhabdomyomas.

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.

Fetal cardiac rhabdomyoma due to paternal mosaicism of TSC2: A case report

RATIONALE

Rhabdomyoma is the most common type of fetal heart tumors and 50% to 60% of cardiac rhabdomyomas are associated with tuberous sclerosis complex (TSC). TSC is characterized by hamartomas in multiple organ systems including the brain, heart, skin, lungs, and kidneys, resulting in complications such as learning difficulties, epilepsy, behavioral problems, and renal failure. The etiological diagnosis of Rhabdomyoma is very important.

PATIENT CONCERNS

A 22-year-old G2P0 woman chose to terminate the pregnancy at 24 + 4 weeks of gestation because of the presence of a cardiac space-occupying lesion in the fetus.

DIAGNOSES

The pathological diagnosis of cardiac neoplasm tissue was cardiac rhabdomyoma, but the etiology was unknown.

INTERVENTIONS

Targeted exome capture, next-generation sequencing (NGS) and sanger sequencing were performed on peripheral blood lymphocytes and paternal sperm.

OUTCOMES

Targeted exome capture sequencing revealed a novel heterozygous variant (NM_000548, c.2294delC) in the tuberous sclerosis 2 (TSC2) gene. Sanger sequencing of maternal blood samples showed no mutation at this locus, however, suspected low level mosaicism was observed in paternal blood samples. Deep NGS analysis showed that about 7% paternal alleles from peripheral blood leucocytes and 20% paternal alleles from sperm carried the mutation consistent with somatic and germinal mosaicism.

LESSONS

For fetuses suspected of TSC, when pathogenic mutations are detected in the tuberous sclerosis 1 (TSC1) or TSC2 gene, it is recommended that the parents should be screened by deep NGS and their germ cells are screened as well if necessary, which would help to predict the risk of TSC recurrence in the next pregnancy.

Symptomatic and lethal congenital primary cardiac rhabdomyoma

Background

Congenital tumors, including mesenchymal rhabdomyoma, are highly infrequent. The combination of a congenital tumor and rhabdomyoma is rarer yet, even more so when primary origin is in the heart.

Case presentation

We present a case of fetal hydrops fetalis, wherein the post-mortem exam revealed a cardiac tumor more than twice the size of the heart itself; histological study confirmed primary rhabdomyoma involving the left ventricle.

Conclusion

It is essential to keep in mind that fetal tumors should always be differentiated from malformations; in fetuses tissue immaturity must be taken into account for categorization; despite benign labeling, they can be lethal.