RESUMO
BACKGROUND: Congenital infantile fibrosarcoma (CIF) and congenital hemangioma (CH) have similarities on prenatal ultrasound and are rare. CASE SUMMARY: We report 3 cases of fetuses with superficial hypervascular tumors, confirmed by postnatal pathology as CIF (1 case) and CH (2 cases, including 1 in a twin fetus). In Case 1, a mass with a rich blood supply in the fetal axilla was discovered by prenatal ultrasound at 28+0 wk of gestation. The postpartum pathological diagnosis was CIF, the mass was surgically removed, and the prognosis of the child was good. In Case 2, at 23+1 wk of gestation, a mass was discovered at the base of the fetus's thigh on prenatal ultrasound. The postpartum pathological diagnosis was CH. After conservative treatment, the mass shrank significantly. Case 3 occurred in a twin fetus. At 30+0 wk of gestation, prenatal ultrasound revealed a bulging mass with a rich blood supply on the abdominal wall of one of the fetuses. Three weeks later, the affected fetus died, and the unaffected baby was successfully delivered by emergency cesarean section. The affected fetus was pathologically diagnosed with CH. CONCLUSION: Prenatal ultrasound can provide accurate information, such as the location, size and blood supply of a surface mass in a fetus. We found similarities between CIF and CH in prenatal ultrasound findings. Although it is difficult to distinguish these conditions by prenatal ultrasound alone, for superficial hypervascular tumors that rapidly increase in size in a short period, close ultrasound monitoring of the fetus is required to quickly address possible adverse outcomes.