Neuroimaging Findings in Fetal Hemimegalencephaly: Case Study and Review.

BACKGROUND: Limited information exists in the prenatal literature regarding the neuroimaging features of fetal hemimegalencephaly. SUMMARY: This report describes ultrasound and magnetic resonance imaging (MRI) findings in a second-trimester fetus with an isolated, severe form of hemimegalencephaly. The most prominent imaging findings included unilateral enlarged cerebral hemisphere and ipsilateral ventriculomegaly causing cerebral asymmetry, midline shift, and macrocephaly. Abnormal cortical development imaging signs were also evident. A literature review encompassing 23 reports describing 36 cases, including ours, is presented. KEY MESSAGES: Characteristic ultrasound findings for the diagnosis of hemimegalencephaly are not always apparent prenatally. Asymmetric ventriculomegaly emerges as the most common but nonspecific presenting feature during routine second- or third-trimester ultrasound scans. Subsequent high-resolution prenatal neurosonography and fetal MRI facilitate definitive prenatal diagnosis, showcasting associated features primarily related to cortical migration, differentiation, and maturation. Postnatally, the prognosis is poor due to intractable seizures, hemiplegia, and progressive neurodevelopmental delay.

Trisomy 18 in a First-Trimester Fetus with Thoraco-Abdominal Ectopia Cordis.

Introduction: Fetuses with trisomy 18 will occasionally also have ectopia cordis. Case report: A routine ultrasound scan at 12 weeks' gestation revealed a large fetal anterior thoraco-abdominal wall defect with an extrathoracic heart and a liver-containing omphalocele. Chorionic villus sampling revealed a 47,XY,+18 karyotype. Additional anomalies detected after termination of the pregnancy included a cleft lip and palate and left radial agenesis. Conclusions: The prenatal diagnosis of ectopia cordis associated with aneuploidy can be made in the first trimester of pregnancy. An extrathoracic heart located in a liver-containing omphalocoele should be considered a thoraco-abdominal ectopia cordis rather than pentalogy of Cantrell.