Prenatal diagnosis of lissencephaly: a case report.

We describe the abnormal sonographic findings in the brain of a 26-week fetus, which increased the suspicion of isolated lissencephaly. Follow-up ultrasound examination and MRI depicted diffuse cortical agyria, microcephaly, hypotelorism, and proptosis. Cordocentesis showed a normal 46,XY karyotype, and no short arm deletion of chromosome 17 was detectable. Postmortem examination confirmed complete agyria of the whole fetal brain. Early detection of fetal microcephaly and other cranial abnormalities can be a sign of isolated lissencephaly and need to be evaluated carefully with ultrasound and MRI for detection of abnormal cortical development of the fetal brain.