180 The association of prenatally diagnosed cardiac rhabdomyoma and tuberous sclerosis complex

Abstract

<h3></h3> Although rare, cardiac rhabdomyomas (CRs) are the most common fetal cardiac tumors. They may be the earliest manifestation of tuberous sclerosis complex (TSC). TSC is diagnosed in 75-80% cases of multiple fetal CRs and in 30% of single cases. We retrospectively reviewed the clinical outcome of fetal CR cases. All cases of prenatally diagnosed rhabdomyoma in a single tertiary centre from 2009 to 2019 were ascertained from medical records. We identified 14 fetuses with prenatally diagnosed CRs. Mean period of follow-up was 4 years (range 4m-9y). Two fetuses were twins (BC/BA), both affected by CR with family history of TSC, and one fetus of the dichorionic pair was not affected by rhabdomyoma. The mean GA at diagnosis was 29 weeks (range 21-35). There were eleven fetuses with multiple, and three with a solitary tumor. The right and left ventricle as well as the intraventricular septum were equally affected with a slight predominance of the left ventricle. The cardiac atrium was affected in two cases. The size ranged from small tumors of several mm in diameter up to dimensions of 20x20 mm. Sixty percent were &lt;20 mm in diameter. Two of fetuses were affected by hemodynamically relevant cardiac obstruction (LVOT), and in four arrhythmias (SVES, VES, WPW syndrome, and AV block) were observed. No hydrops fetalis or fetal perinatal demise were observed. In 11 (79%) TSC was confirmed clinically or by mutational analysis. After birth, most rhabdomyomas demonstrated a stable (14%, n=2) or spontaneous regressive growth pattern (57%, n=8). In four children (29%) tumors entirely disappeared. No progression of tumor size or number was observed. After birth in five (36%) children the conduction abnormalities were confirmed by ECG and responded well to the anti-arrhythmic medication and two children were affected by LVOT obstruction. Cerebral manifestations (tubers and/or nodules) were detected by brain MRI in 9 patients (3 prenatally). Subependymal giant cell astrocytoma was diagnosed in 3 cases, 2 received treatment with mTOR inhibitor, and one child underwent VP shunt due to enlarging SEGA causing obstructive hydrocephalus. Six (55%) of the children with TSC suffered from epilepsy and psychomotoric development delay. Although CRs are benign from the cardiovascular standpoint, and have a natural history of spontaneous regression, their close association with TSC prompt for early prenatal diagnosis and family counselling regarding the dismal long-term prognosis. Recent literature suggests that early therapy with mTOR inhibitors may prevent the development of TS manifestations.