Prenatal diagnosis of giant cardiac rhabdomyoma in tuberous sclerosis complex: a new therapeutic option with everolimus

Tuberous sclerosis complex (TSC) is a genetic disorder characterized by abnormal cell proliferation and tumor growth in a number of organ systems, primarily the brain, kidneys, eyes and heart. Clinical symptoms vary according to the location of the tumor. The most common disorders are seizures, neurodevelopmental disorders, renal failure and arrhythmias. TSC was found to be influenced by inhibitors of the protein kinase mammalian target of rapamycin (mTOR), which regulates abnormal cellular proliferation. mTOR inhibitors have been studied effectively in patients with subependymal giant-cell astrocytomas and renal angiolipomas in the context of TSC. We describe a prenatally diagnosed case of giant rhabdomyoma, due to right ventricular outflow tract obstruction, which presented as a duct-dependent lesion. Postnatal treatment with the mTOR inhibitor everolimus initiated significant regression of the cardiac tumor. This finding suggests that mTOR inhibitor therapy is an option for giant rhabdomyomas that develop in the neonatal period.

No impact of endogenous prothrombotic conditions on the risk of central venous line-related thrombotic events in children: results of the KIDCAT study (KIDs with Catheter Associated Thrombosis)

BACKGROUND AND OBJECTIVE

Central venous lines (CVLs) are the major exogenous risk factor for deep venous thrombosis (DVT) in children. The study objective was to assess whether endogenous prothrombotic conditions contribute to the risk of CVL-related DVT in children.

METHODS

This was a cohort study of consecutive children with heart disease requiring CVLs for perioperative care. CVLs were inserted percutaneously in the upper venous system and patients received prophylaxis with continuous unfractionated heparin (50 u kg(-1)  d(-1) ). Blood samples to test for prothrombotic conditions were collected prospectively and assayed in a blinded fashion. Outcome assessment was by screening for DVT by venography, venous ultrasound and echocardiography.

RESULTS

The study population consisted of 90 children, median age 2.7 years (0 months-18 years). Prevalence rates of antithrombin deficiency, protein C deficiency, protein S deficiency, heterozygous factor V Leiden, prothrombin G20210A mutation, methylentetrahydrofolate C677TT genotype, hyperhomocysteinemia, lupus anticoagulant, anticardiolipin antibodies and increased levels of lipoprotein (a) were within the range reported for the general population. At least one prothrombotic condition was present in 38% of children and combined abnormalities in 8%. The incidence of DVT was 28% (25/90), and most DVTs were asymptomatic. None of the prothrombotic conditions showed a significant association with DVT. The population attributable risk (i.e. the risk of DVT in the overall population attributable to a specific condition) did not exceed 2.2%.

CONCLUSION

Prothrombotic conditions did not have an important impact on the risk of DVT in children with short-term CVLs. The results of the study suggest that screening for prothrombotic conditions is not justified in this setting.

Long-term follow-up of pediatric patients treated with mitoxantrone for multiple sclerosis

The chemotherapeutic agent mitoxantrone is approved for the treatment of aggressive multiple sclerosis (MS) in adults. Its use, however, is limited by the risk of severe adverse events including cardiotoxicity, myelosuppression, liver toxicity and secondary leukemia. The aim of this retrospective study is to present data on the safety, tolerability and efficacy of mitoxantrone in a small cohort of children with MS. 4 pediatric MS patients with a high relapse rate or severe, disabling relapses were treated with mitoxantrone and followed for 3.8-18 years. The cumulative dose of mitoxantrone was 36, 68, 84 and 120 mg/m (2), respectively. The frequency and severity of relapses as well as disability scores, decreased in the year after treatment onset. Short-term adverse events were transient in all cases. Cardiac monitoring by transthoracic echocardiography (TTE) showed asymptomatic left ventricular dysfunction during treatment in 1 patient, which was again normal at the next assessment. Long-term adverse events, including late-onset mitoxantrone-induced cardiotoxicity or secondary leukemia did not occur during the follow-up period. In our cohort of pediatric MS patients, mitoxantrone showed short-term reduction of disease activity and no long-term adverse events on follow-up. However, the risk of mitoxantrone-induced cardiotoxicity or toxic leukemia remains a life-long threat.