Prenatal diagnosis and outcomes of fetal cardiac tumors: a 10-year single-center study of 81 cases.

OBJECTIVE: This study aimed to comprehensively analyze the prenatal phenotype, genetic basis, and postnatal trajectory of a large cohort of fetuses with fetal cardiac tumors (FCTs). METHODS: This retrospective study included 81 fetuses diagnosed with FCTs at our center between 2014 and 2024. We reviewed prenatal ultrasound and MRI findings, genetic testing results, and postnatal follow-up data, extending to a minimum follow-up period of 1 year. Tumor characteristics, complications, and predictors of tuberous sclerosis complex (TSC) and adverse outcomes were analyzed. RESULTS: Among the 81 cases FCTs, cardiac rhabdomyoma (CR) was the most common tumor (66 cases, 81.5%), followed by fibroma (n = 5, 6.2%), myxoma (n = 3, 3.7%), hemangioma (n = 1, 1.2%), teratoma (n = 1, 1.2%), and unclassified tumors (n = 5, 6.2%). Complications occurred in 30.9% of cases and were associated with tumor volume and location rather than tumor multiplicity. TSC was identified in 70.0% (42/60) of fetuses with CR. Tumor multiplicity was significantly associated with TSC (78.7% for multiple vs. 38.5% for solitary lesions, p = 0.013), whereas maximum tumor volume did not differ significantly between TSC-associated and isolated CR (p = 0.646). Cranial MRI increased prenatal TSC detection by 23% compared with ultrasound alone (69.2% vs. 46.2%). Among the 48 live-born infants (live birth rate 59.3%), 22 cases showed tumor regression or disappearance during follow-up, all of which were CRs. One case each of CR, fibroma, and an unclassified tumor showed gradual enlargement postnatally. Six cases underwent surgical resection, and the remaining tumors remained stable. Among children with TSC, 72.7% (16/22) developed epilepsy, and 36.4% (8/22) had neurodevelopmental disorders, whereas all TSC-negative children had normal neurodevelopment. CONCLUSION: Tumor multiplicity, rather than size, was more strongly associated with TSC in fetal CR. Ultrasound combined with MRI improved the prenatal detection rate of fetal TSC. In the absence of hemodynamic compromise and TSC, FCTs had a favorable prognosis. These findings support a management algorithm based on tumor type, multiplicity, tumor size/location, and genetic testing.