Introduction:
Tuberous sclerosis complex (TSC) is a neurocutaneous disorder affecting 1 in 6,000 individuals. In the course of TSC multiple, usually benign tumours develop in many organs. Moreover, 70-90% of TSC patients develop epilepsy, mostly in the first months of life. Seizures are also associated with cognitive impairment. Recent studies showed the beneficial role of preventative antiepileptic treatment in TSC. Therefore, early TSC diagnosis is becoming pivotal for epilepsy management. Cardiac rhabdomyomas are frequent and are the earliest detectable signs of TSC. They are often revealed prenatally.

Aim of the study:
To assess and compare the incidence of TSC among children with single and multiple cardiac tumours

Material and methods:
A retrospective chart review was performed in 76 children with single or multiple cardiac tumours, who were referred to the Children’s Memorial Health Institute for further diagnosis of TSC.

Results:
Single and multiple cardiac tumours were observed in 14.5% and 85.5% of patients, respectively, and 71.1% of tumours were diagnosed prenatally. The diagnosis of TSC was established in 92.1% of children. The correlation between multiple tumours and TSC diagnosis was observed (p < 0.01). Moreover, in the group of children with multiple cardiac lesions TSC was diagnosed more often than in the group with single tumours (95.4% vs. 72.7%, p < 0.05).

Conclusions:
Tuberous sclerosis complex may be diagnosed both in patients with single and multiple cardiac rhabdomyomas. However, in patients with multiple lesions TSC is confirmed significantly more often. Therefore, multiple cardiac tumours may be considered as an early biomarker of TSC.