Cardiac rhabdomyomas in tuberous sclerosis - prenatal and neonatal findings

 ThisThis is a case of fetal cardiac rhabdomyomas leading to the early diagnosis of tuberous sclerosis.At birth, clinical examination revealed a few achromic macules. Genetic investigations revealed a familial condition.

Multiples prenatal cardiac tumors have almost no differential: rhabdomyomas, with typical bright hyperechogenicity.Spontaneous involution is expected after birth. In some cases, they may be temporarily obstructive and hinder cardiac outflow.In approx. 40-60% of cases in some series, fetal rhabdomyomas predicts tuberous sclerosis. Hence prenatal MR is performed to look out for tubers and subependymal nodules. Prenatal tubers display reversed MR signal compared to paediatric and adult tubers in a myelinized brain. 

Tubers and subependymal nodules may appear months, or years later :, hence, a negative prenatal brain MRI does not rule out Tuberous Sclerosistuberous sclerosis.Genetics research for the most common mutation of TSC1 and TSC2 genes do contribute to the prenatal diagnosis for counselingcounselling, especially in case of a negative prenatal brain MRI. Tuberous sclerosis [OMIM(OMIM #191100) can be DE NOVO,de novo or inherited in a dominant autosomal fashion. However, penetrance and phenotypalphenotypic expression are variable, and clinical symptoms may be absent in a mildly affected individualindividuals.

Multiple bright hyperechoic pseudotumoral images within the myocardium, in the interventricular septum, the right atrium and both ventricles. Brain US examination limited at 32WG32 weeks gestation.

Left frontal hypoT2 hyperT1 image contrasting with the surrounding white matter substance (which is physiologically hyperT2 hypoT1 in a non myelinized-myelinated brain).No subependymal nodules were seen.

Normal brain biometries, developpmental morphology (midline, migration and gyration).

Same image as in prenatal MR: frontal left hypoT2 hyperT1 lesion.

Normal myelinization of paracentral gyri as expected.