Hepatic Tumor as Antenatal Presentation of Costello Syndrome

Abstract

A large hepatic mixed echoic mass occupying the left fetal abdomen was identified at 266/7 weeks. The mass showed peripheral and internal vascularity. Other ultrasound findings included edema of the fetal head and face, macrosomia, shortened long bones, abnormal posture of hands, small stomach, polyhydramnios and biventricular hypertrophy. Fetal magnetic resonance imaging confirmed a hypervascular mass replacing the lateral left hepatic lobe, suggestive of a congenital hemangioma. The fetus was delivered by cesarean section at 282/7 weeks. The baby was stabilized at day 3 of life, and underwent successful selective tumor embolization. The baby remained stable for 3 days, then deteriorated with a progressive thickening of the myocardium. The child then passed away on day 11 from severe progressive hypertrophic cardiomyopathy, with almost complete obliteration of the left ventricular cavity; an autopsy was declined. Postnatal investigations reported a de novo heterozygous pathogenic HRAS variant (NM_005343.3(HRAS): c.35_36 delinsTT, p.Gly21Val), previously reported in 8 cases associated with the early, lethal form of Costello syndrome.