Background: Lipoblastoma is one of the rare masses in childhood and its diagnosis is very uncommon in the perinatal period, so we reported a case with a diagnosis of this mass during pregnancy.
Case Report: In a routine third-trimester ultrasound at 28 weeks, a hyperechoic mass in the size of 27*30mm was detected in between labia majora. However, no abnormal findings were found in perinatal care before this gestational age. Finally, after the birth, at 40 weeks of gestation, the mass was resected and now the baby is in good condition and no recurrence has occurred. There was also an anorectal anomaly associated with this mass in our patient who underwent Anorectoplasty surgery.
Conclusion: Due to the rarity of these tumors, it is important to diagnose them in the perinatal period and to investigate other associated anomalies.