FETAL RHABDOMYOMA: PRENATAL DIAGNOSIS, CLINICAL OUTCOME, AND INCIDENCE OF ASSOCIATED TUBEROUS SCLEROSIS COMPLEX RIMA S. BADER, MD, DAVID CHITAYAT, MD, FRCPC, EDMOND KELLY, MD, GREG RYAN, MD, J EFFREY F. SMALLHORN, MD, ANTS TOI, MD, AND LISA K. HORNBERGER, MD Objectives We reviewed our institution’s experience with fetal cardiac rhabdomyoma to document the clinical outcome and incidence of associated tuberous sclerosis complex (TSC) and compared our findings with those of patients diagnosed with cardiac rhabdomyoma after birth. Study design We reviewed the medical records of all cases diagnosed prenatally and postnatally with cardiac rhabdomyoma between January 1990 and June 2002. Results Twenty fetuses with cardiac rhabdomyoma were diagnosed at 28.4 ± 6.0 weeks’ gestational age. Of 19 continued pregnancies, there was one spontaneous intrauterine death, and 18 were delivered at term. Although none had prenatal hemodynamic complications, after birth seven had cardiac symptoms requiring medical (n = 4) or surgical intervention (n = 3). On follow-up, 15 of 19 with available outcome had TSC (79%), including six with neurodevelopmental disease. Over the same period, 26 patients were diagnosed with cardiac rhabdomyoma postnatally. Most (77%) were referred for cardiac assessment after findings suggesting TSC. On follow-up, TSC was confirmed in 25 (96%), including 22 with neurodevelopmental disease. The incidence of cardiac symptoms and TSC was not statistically different between the prenatal and postnatal diagnosis groups. Conclusions Cardiac rhabdomyomas are benign from the cardiovascular standpoint in most affected fetuses. As observed in postnatally diagnosed cardiac rhabdomyoma, TSC is diagnosed in most cases of fetal cardiac rhabdomyoma. (J Pediatr 2003;143:620-4) P rimary cardiac tumors are rare, with an estimated incidence of 0.27% among pediatric autopsies. 1 The most common type of cardiac tumor identified in infancy and childhood is rhabdomyoma. 1 Postnatal diagnosis of cardiac rhabdomyoma (CR) is often made when signs and symptoms of tuberous sclerosis complex (TSC) are identified, 2-5 or when there is a family history prompting cardiac assessment as part of the clinical work-up. Only occasionally does a patient present with cardiac symptoms that necessitate medical or surgical intervention. Because many affected infants have no cardiac symptoms, CRs not associated with TSC may go unrecognised. Therefore, the true incidence of CR in infants and children and the frequency of the associated TSC in all affected infants remain unclear. As is true after birth, CRs are by far the most common cardiac tumor diagnosed in utero. 6 In contrast, however, the prenatal diagnosis of CR most often occurs after referral for the finding of a cardiac tumor or fetal dysrhythmia on routine obstetrical ultrasound assessment without other obvious features of TSC at the time of diagnosis. Knowledge of the outcome of affected fetuses and the true incidence of TSC in fetal CR is critical for accurate prenatal counseling and planning of prenatal treatment. In the current study, we reviewed our institution’s experience with fetal CR encountered over a 12-year period to document the diagnosis, clinical outcome, and incidence of TSC in affected fetuses. We compared our findings with those of infants and children diagnosed with CR only after birth over the same period. We hypothesized that patients diagnosed before birth with CR From the Department of Pediatrics, Division of Cardiology, Fetal Cardiac Program; the Division of Clinical and Metabolic Genetics, the Hospital for Sick Children; and the Department of Pediatrics, the Department of Obstet- rics and Gynecology, the Prenatal Diagnosis and Medical Genetics Pro- gram, and the Department of Diag- nostic Imaging, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada. Submitted for publication Dec 9, 2002; revision received May 5, 2003; accepted Aug 6, 2003. Reprint requests: Lisa K. Hornberger, MD, Division of Cardiology, Fetal Car- diac Program, Hospital for Sick Chil- dren, 555 University Ave, Toronto, Ontario, Canada M5G 1X8. E-mail: hornberg@sickkids.on.ca. Copyright ª 2003 Mosby, Inc. All rights reserved. 0022-3476/2003/$30.00 + 0 10.1067/S0022-3476(03)00494-3 CR Cardiac rhabdomyoma TSC Tuberous sclerosis complex 620