Molecular genetic, cardiac and neurodevelopmental findings in cases of prenatally diagnosed rhabdomyoma associated with tuberous sclerosis complex

Objective Rhabdomyoma is the most common type of cardiac tumor in fetuses and is often associated with tuberous sclerosis complex (TSC) with neurologic sequelae. The purpose of this study was to investigate the cardiac and neurodevelopmental outcomes of fetal rhabdomyoma. Methods We reviewed the clinical characteristics of 23 cases of cardiac rhabdomyoma diagnosed prenatally by fetal echocardiography at the Asan Medical Center between January 1998 and December 2009. We also reviewed postnatal results of brain magnetic resonance imaging, echocardiography, renal ultrasound examination and molecular genetic analysis to confirm the presence of cardiac rhabdomyoma with or without TSC. Results Among 23 cases, outcome data were available for 17 (73.9%) and six cases (26.1%) were lost to follow-up. The survival rate was 100.0% (17/17). Among the 17 cases with outcome data, spontaneous tumor regression occurred in eight (47.1%), and no change in tumor size and number was observed in the remaining nine cases (52.9%). There was no evidence of long-term cardiac dysfunction caused by persisting rhabdomyomas, regardless of tumor size. TSC was found in nine patients (52.9%), of whom five (55.6%) showed neurodevelopmental morbidity. We identified mutations in one of the TSC1 or TSC2 genes in four of nine TSC infants whose parents allowed us to perform molecular genetic analysis. Three of these (75.0%) were found to have neurologic impairment. Seven (77.8%) of nine TSC cases were non-familial. Conclusions The overall outcome of isolated cardiac rhabdomyoma appears to be favorable. We suggest that systematic postnatal evaluation of TSC be performed even in cases of cardiac rhabdomyoma without a family history of TSC. Molecular characterization of TSC1 and TSC2 might be helpful in predicting short- and long-term neurodevelopmental outcomes.