OP07.09: Fetal asymmetric ventriculomegaly, corpus callosal malformation and interhemispheric cyst: an imaging triad

Abstract

Results: Associated brain anomalies were observed in 7 cases (70%). 4 fetuses with isolated mild ventriculomegaly (VM), 1 fetus with schizencephaly, 1 fetus with ventriculomegaly, ArnoldChiary malformation and myelomeningocele, 1 with mild VM and microcephaly. 1 patient demonstrated a partial agenesis of corpus callosum additional to mild VM. In 3 patients we saw communicating lateral ventricles in their middle portion. One of these patients showed an aneuploidy (monosomie 21 mosaicism). Only two parents decided to terminate the pregnancy: the parents of the fetus with schicencephaly and the parents of the fetus with aneuploidy. To parents information five children were developing normally aged 4 months to a year and a half: 3 with isolated ASP und 1 with partial corpus callosum agenesis and mild ventriculomegaly and 1 with communicating of the middle portion of the lateral ventricles. Two children had mild signs of septo-optic dysplasia (SOD) with optic nerve and pituitary dysfunction, in one case associated with moderate mental retardation. Conclusions: Prenatal diagnosis of absent septum pellucidum is often associated with additional brain anomalies. Chromosomal anomalies are rare. In cases of isolated ASP prenatal counselling of the parents is very difficult. It is currently impossible to differentiate SOD from isolated absence of the septum pellucidum